Answer:
[tex]x=\frac{5}{7}[/tex]
Step-by-step explanation:
[tex]3x - 2 = 3 - 4x[/tex]
Add [tex]2[/tex] and [tex]4x[/tex] on both sides of the equation.
[tex]3x - 2 +2+4x= 3 - 4x+2+4x[/tex]
[tex]3x+4x=-4x+5+4x[/tex]
[tex]7x=5[/tex]
Divide [tex]7[/tex] on both sides of the equation.
[tex]\frac{7x}{7}=\frac{5}{7}[/tex]
[tex]x=\frac{5}{7}[/tex]
Based on aâ poll, among adults who regret gettingâ tattoos, 18â% say that they were too young when they got their tattoos. Assume that eight adults who regret getting tattoos are randomlyâ selected, and find the indicated probability. Complete partsâ (a) throughâ (d) below.
a. Find the probability that none of the selected adults say that they were too young to get tattoos.
b. Find the probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c. Find the probability that the number of selected adults saying they were too young is 0 or 1.
d. It we randomly select 9 adults. Is 1 a significantly low number who day that they were too young to get tattoos?
Answer:
a) 20.44% probability that none of the selected adults say that they were too young to get tattoos.
b) 35.90% probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c) 56.34% probability that the number of selected adults saying they were too young is 0 or 1.
d) No
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they say they were too young when they got their tattoos, or they don't say that. Each adult is independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
18% say that they were too young when they got their tattoos.
This means that [tex]p = 0.18[/tex]
Eight adults who regret getting tattoos are randomly selected
This means that [tex]n = 8[/tex]
a. Find the probability that none of the selected adults say that they were too young to get tattoos.
This is P(X = 0).
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{8,0}.(0.18)^{0}.(0.82)^{8} = 0.2044[/tex]
20.44% probability that none of the selected adults say that they were too young to get tattoos.
b. Find the probability that exactly one of the selected adults says that he or she was too young to get tattoos.
This is P(X = 1).
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 1) = C_{8,1}.(0.18)^{1}.(0.82)^{7} = 0.3590[/tex]
35.90% probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c. Find the probability that the number of selected adults saying they were too young is 0 or 1.
Either a. or b.
20.44 + 35.90 = 56.34
56.34% probability that the number of selected adults saying they were too young is 0 or 1.
d. It we randomly select 9 adults. Is 1 a significantly low number who day that they were too young to get tattoos?
Now [tex]n = 9[/tex]
It is significantly low if it is more than 2.5 standard deviations below the mean.
The mean is [tex]E(X) = np = 9*0.18 = 1.62[/tex]
The standard deviation is [tex]\sqrt{V(X)} = \sqrt{n*p*(1-p)} = \sqrt{9*0.18*0.82} = 1.15[/tex]
1 > (1.62 - 2.5*1.15)
So the answer is no.
In order to solve for the variable in the equation 2 (x + 3) + 5 x = 3 (2 x minus 1), Jaleesa begins by applying the distributive property, then combines like terms. Which equation is the result of these steps?
Answer:
7x+6 = 6x-3
Step-by-step explanation:
2 (x + 3) + 5 x = 3 (2 x - 1)
Distribute
2x+6+5x = 6x-3
Combine like terms
7x+6 = 6x-3
Answer:
7x + 6 = 6x - 3 Option A
Step-by-step explanation:
Now Jalesa wants to simplify this equation.
Firstly applying the distributive property
Distribute the 2 over the parenthesis and distribute the over the parenthesis
that is,
2*x + 2*3 + 5x = 3*2x - 3*1
2x + 6 + 5x = 6x - 3
After that combine like terms
2x + 5x + 6 = 6x - 3
7x + 6 = 6x - 3
Result is:
7x + 6 = 6x - 3
That's the final answer.
{(1,3),(2,5)(3,-4),(4-3),(5,1)} a function or not a function
Answer:
yes the above is a function.
What’s the correct answer for this question?
Answer:
A.
Step-by-step explanation:
Volume of cone = 1/3πr²h
= (1/3)(3.14)(1.5)²(5)
= (1/3)(3.14)(2.25)(5)
= (1/3)(35.3)
= 11.78
≈ 11.8 cubic inches
The diagram shows a rectangle and a square.
Diagram
accuratel
The rectangle is 2 cm long and 6 cm wide.
The perimeter of the rectangle is the same as the perimeter of the square.
Work out the length of one side of the square.
Answer:
4 cm
Step-by-step explanation:
The side of the square will be the average of the two sides of the rectangle with the same perimeter.
Formulas for the perimeters are ...
P = 2(L+W)
P = 4s
Equating these gives ...
4s = 2(L+W)
s = (L +W)/2 . . . . . divide by 4
For the given side lengths, ...
s = (2 cm +6 cm)/2 = (8/2) cm = 4 cm
The length of one side of the square is 4 cm.
In a certain city district the need for money to buy drugs is stated as the reason for 70% of all thefts. Find the probability that among the next 7 theft cases reported in this district, exactly 3 of them resulted from the need to buy drugs.
Answer:
9.72% probability that among the next 7 theft cases reported in this district, exactly 3 of them resulted from the need to buy drugs.
Step-by-step explanation:
For each theft, there are only two possible outcomes. Either the need to buy drugs is the reason of the theft, or it is not. Each theft is independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
In a certain city district the need for money to buy drugs is stated as the reason for 70% of all thefts.
This means that [tex]p = 0.7[/tex]
Find the probability that among the next 7 theft cases reported in this district, exactly 3 of them resulted from the need to buy drugs.
This is P(X = 3) when n = 7. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 3) = C_{7,3}.(0.7)^{3}.(0.3)^{4} = 0.0972[/tex]
9.72% probability that among the next 7 theft cases reported in this district, exactly 3 of them resulted from the need to buy drugs.
Help please!!! Everything is in the picture.
Answer:
3u-2v = [tex]\sqrt{505\\}[/tex]
5u-v = [tex]\sqrt{1,157}[/tex]
2u-3v = [tex]\sqrt{1,300}[/tex]
u+4v = [tex]\sqrt{4,505}[/tex]
Step-by-step explanation:
I just started by doing the results for each of the operations given.
3u-2v:
3u = (-9, 24) 2v = (-28, 12)
Do the operation of 3u-2v and you get a resultant vector of (19, 12).
You calculate this by doing the square root of 19^2 + 12^2, which is the square root of 505.
5u-v:
5u = (-15, 40) v = (-14, 6)
Do the operation of 5u-v and you get a resultant vector of (-1, 34).
You calculate this by doing the square root of (-1)^2 + 34^2, which is the square root of 1,157.
2u-3v:
2u = (-6, 16) 3v = (-42, 18)
Do the operation of 2u-3v and you get a resultant vector of (36, -2).
You calculate this by doing the square root of 36^2 + (-2)^2, which is the square root of 1,300.
3u+2v:
3u = (-9, 24) 2v = (-28, 12)
Do the operation of 3u+2v and you get a resultant vector of (-37, 36).
You calculate this by doing the square root of (-37)^2 + 36^2, which is the square root of 2,665. This is not a given tile, so we can just ignore this one.
u+4v:
u = (-3, 8) 4v = (-56, 24)
Do the operation of u+4v and you get a resultant vector of (-59, 32).
You calculate this by doing the square root of (-59)^2 + 32^2, which is the square root of 4,505.
Since this is a given tile, I didn't do 7u-2v, but you would use the same methodology.
Determine the value(s) of h such that the matrix is the augmented matrix of a consistent linear system. [Start 2 By 3 Matrix 1st Row 1st Column 1 2nd Column 4 3rd Column negative 2 2nd Row 1st Column 3 2nd Column h 3rd Column negative 6 EndMatrix ]
Answer:
Step-by-step explanation:
Consider the augments matrix (the right most column is the extra vector).
[tex]\left[\begin{matrix} 1 & 4 & -2 \\3 & h & -6\end{matrix}\right][/tex]
By multypling the first row by 3 and substracting it from the second row and saving the result in the second row we get the matrix
[tex]\left[\begin{matrix} 1 & 4 & -2 \\0 & h-12 & 0\end{matrix}\right][/tex]
Note that since the value of the third column in the second row is 0, any value of h gives us a consistent system. An inconsistent system is when we get a row of zeros that is equal to a number different from 0.
Which of the following is the solution to |x-1|=8
Answer:
-7,9
Step-by-step explanation:
x-1=-8
x=-7
x-1=8
x=9
maths
Ella mixes cordial and water in the ratio of 1:4 how much water should be mixed with 50ml or cordial
Sidney made $35 less than four times Casey’s weekly salary. If x represents Casey’s weekly salary, write an expression for Sidney’s weekly salary.
Answer: [tex]y=4x-35[/tex]
y = Sidney’s weekly salary
x = Casey’s weekly salary
Answer: y=4x-35
x is Casey's salary
Y is Sidney's salary
Step-by-step explanation:
Sidney makes a quarter of Casey,
y=4x,
Then it also states that he makes 35 less than the first equation.
Therefore,
Y=4x-35
3.14 The waiting time, in hours, between successive speeders spotted by a radar unit is a continuous random variable with cumulative distribution function F(x) = 0, x< 0, 1 − e−8x, x ≥ 0. Find the probability of waiting less than 12 minutes between successive speeders (a) using the cumulative distribution function of X; (b) using the probability density function of X.
Answer:
(a) The probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.
(b) The probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.
Step-by-step explanation:
The cumulative distribution function of the random variable X, the waiting time, in hours, between successive speeders spotted by a radar unit is:
[tex]F(x)=\left \{ {{0;\ x<0} \atop {1-e^{-9x};\ x\geq 0}} \right.[/tex]
(a)
Compute the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function as follows:
[tex]12\ \text{minutes}=\frac{12}{60}=0.20\ \text{hours}[/tex]
The probability is:
[tex]P(X<0.20)=|F (x)|_{x=0.20}[/tex]
[tex]=(1-e^{-8x})|_{x=0.20}\\\\=1-e^{-8\times 0.20}\\\\=0.7981[/tex]
Thus, the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.
(b)
The probability density function of X is:
[tex]f_{X}(x)=\frac{d F (x)}{dx}=\left \{ {{0;\ x<0} \atop {8e^{-8x};\ x\geq 0}} \right.[/tex]
Compute the probability of waiting less than 12 minutes between successive speeders using the probability density function as follows:
[tex]P(X<0.20)=\int\limits^{0.20}_{0} {8e^{-8x}} \, dx[/tex]
[tex]=8\times [\frac{-e^{-8x}}{8}]^{0.20}_{0}\\\\=[-e^{-8x}]^{0.20}_{0}\\\\=(-e^{-8\times 0.20})-(-e^{-8\times 0})\\\\=-0.2019+1\\\\=0.7981[/tex]
Thus, the probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.
Which graph represents viable values for y = 2x, where x is the number of pounds of rice scooped and purchased from a bulk bin at the grocery store and y is the total cost of the rice? On a coordinate plane, a straight line with a positive slope begins at point (0, 0), and ends at point (2.5, 5). On a coordinate plane, blue diamonds appear at points (0, 0), (1, 2), (2, 4). On a coordinate plane, a straight line with a positive slope begins at point (negative 2.5, negative 5), crosses the x- and y-axis at point (0, 0), and ends at point (2.5, 5). On a coordinate plane, blue diamonds appear at points (negative 2, negative 4), (negative 1, negative 2), (0, 0), (1, 2), (2, 4). Mark this and return
Answer:
On a coordinate plane, a straight line with a positive slope begins at point (0, 0), and ends at point (2.5, 5)
Step-by-step explanation:
The distinction between "straight line" and "blue diamonds" is that the straight line represents the relation for all possible values of x. The blue diamonds show the values of y for very specific values of x.
Since x is the amount of rice from a bulk bin, we assume it can take any non-negative value. Hence, the graphs with negative values or with "blue diamonds" are not appropriate.
The straight-line graph in the first quadrant is the best choice.
Answer:
The answer is graph 1
Step-by-step explanation:
On a coordinate plane, a straight line with a positive slope begins at point (0, 0), and ends at point (2.5, 5).
Given the following data, find the weight that represents the 53rd percentile.
Weights of Newborn Babies9.4 7.5 5.4 7.5 7.1
6.0 8.1 5.7 7.1 6.6
9.4 5.8 8.7 5.7 9.3
Answer:
Step-by-step explanation:
Rearranging the weights in ascending order, it becomes
5.4, 5.7, 5.7, 5.8, 6.0, 6.6, 7.1, 7.1, 7.5, 7.5, 8.1, 8.7, 9.3, 9.4, 9.4
The formula for determining the percentile is expressed as
n = (P/100)N
Where
n represents the value of the given percentile
P represents the given percentile
N represents the number of items(weights)
From the information given, the number of items, n is 15
P = 53
Therefore,
n = (53/100) × 15
n = 7.95
n = 8
Therefore, the weight that represents the 53rd percentile is the 8th value. It becomes 7.1
53rd percentile is 7.1
SOLVE THE EQUATION SHOW YOUR WORK 3x = 45
Answer:
x = 15
Step-by-step explanation:
3x = 45
x = 45/3
x = 15
Answer:
15
Step-by-step explanation:
3x = 45
Dividing 3 from both sides gives you
[tex]x = 45/3\\\\[/tex]
Now that isolated x.
[tex]45/3 = 15[/tex]
So x = 15
:D
Six measurements were made of the magnesium ion concentration (in parts per million, or ppm) in a city's municipal water supply, with the following results. It is reasonable to assume that the population is approximately normal. Based on a 95% confidence interval for the mean magnesium ion concentration, is it reasonable to believe that the mean magnesium ion concentration may be greater than 199.5? (Hint: you should first calculate the 95% confidence interval for the mean magnesium ion concentration.)
a) The likelihood cannot be determined
b) Yes
c) No
Answer:
Option B is correct.
It is reasonable to believe that the mean magnesium ion concentration may be greater than 199.5 as the confidence interval obtained contains values that are greater than 199.5
Step-by-step explanation:
Complete Question
Six measurements were made of the magnesium ion concentration (in parts per million, or ppm) in a city's municipal water supply, with the following results. It is reasonable to assume that the population is approximately normal.
170 201 199 202 173 153
Based on a 95% confidence interval for the mean magnesium ion concentration, is it reasonable to believe that the mean magnesium ion concentration may be greater than 199.5? (Hint: you should first calculate the 95% confidence interval for the mean magnesium ion concentration.)
A) The likelihood cannot be determined.
B) Yes
C) No
Solution
For this question, obtaining the confidence interval will give a clear solution to the problem.
Since the Confidence Interval for the population mean is basically an interval of range of values where the true population mean can be found with a certain level of confidence, if the range obtained contains values greater than the standard we are comparing against (199.5), then the confidence interval proves that the mean magnesium ion may be greater than 199.5.
But to obtain the confidence interval, we need the mean and standard deviation for the sample.
170, 201, 199, 202, 173, 153
Mean = (sum of variables)/(total number of variables)
Sum of variables = 170+201+199+202+173+153 = 1098
Total number of variables = 6
Mean = (1098/6) = 183
Standard deviation = σ = √[Σ(x - xbar)²/N]
x = each variable
xbar = mean = 183
N = number of variables = 6
Σ(x - xbar)² = (170-183)² + (201-183)² + (199-183)² + (202-183)² + (173-183)² + (153-183)²
= 169 + 324 + 256 + 361 + 100 + 900
= 2110
σ = √(2110/6) = 18.75
Mathematically,
Confidence Interval = (Sample mean) ± (Margin of error)
Sample Mean = 183
Margin of Error is the width of the confidence interval about the mean.
It is given mathematically as,
Margin of Error = (Critical value) × (standard Error of the mean)
Critical value will be obtained using the t-distribution. This is because there is no information provided for the population mean and standard deviation.
To find the critical value from the t-tables, we first find the degree of freedom and the significance level.
Degree of freedom = df = n - 1 = 6 - 1 = 5.
Significance level for 95% confidence interval
(100% - 95%)/2 = 2.5% = 0.025
t (0.025, 5) = 2.57 (from the t-tables)
Standard error of the mean = σₓ = (σ/√n)
σ = standard deviation of the sample = 18.75
n = sample size = 6
σₓ = (18.75/√6) = 7.656
95% Confidence Interval = (Sample mean) ± [(Critical value) × (standard Error of the mean)]
CI = 183 ± (2.57 × 7.656)
CI = 183 ± 19.675
95% CI = (163.325, 202.675)
95% Confidence interval = (163.3, 202.7)
It is reasonable to believe that the mean magnesium ion concentration may be greater than 199.5 as the confidence interval obtained contains values that are greater than 199.5
Hope this Helps!!!
Which data collection method would provide an unbiased sample?
Answer:
The best data collection method or sampling method to provide an unbiased sample is the random sampling method.
Step-by-step explanation:
There are 5 popular known sampling methods or data collection methods.
1) Random Sampling
In random sampling, each member of the population would have an equal chance of being surveyed. One of the best ways to use random sampling is to give all the members of the population numbers and then use computer to generate random numbers and pick the members of the population with those random numbers.
2) Systematic sampling is easier than random sampling. In systematic sampling, a particular number, n, is counted repeatedly and each of the nth member is picked to be sampled.
3) Convenience Sampling
This is the worst sampling technique. It is also the easiest. In Convenience sampling, the surveyor just picks the first set of members of the population that they find and surveys.
4) Stratified Sampling
Stratified sampling divides the population into groups called strata. A sample is taken from each of these strata using either random, systematic, or convenience sampling.
5) Cluster sampling
Cluster Sampling divides the population into groups which are called clusters or blocks. The clusters are selected randomly, and some members or every element/member in the selected clusters is surveyed.
Hope this Helps!!!
Erythropoietin (EPO) is a banned drug used by athletes to increase the oxygen-carrying capacity of their blood. New tests for EPO were first introduced prior to the 2000 Olympic Games held in Sydney, Australia. Chance (Spring 2004) reported that of a sample of 830 world-class athletes, 159 did not compete in the 1999 World Championships (a year prior to the new EPO test). Similarly, 133 of 82:5 potential athletes did not compete in the 2000 Olympic Games. Was the new test effective in deterring an athlete's participation in the 2000 Olympics? If so, then the proportion of nonparticipating athletes in 2000 will be greater than the proportion of nonparticipating athletes in 1999, Use a 98% confidence interval to compare the two proportions and make the proper conclusion.
Answer:
Step-by-step
The null and the alternative hypothesis can be define as follows,
Null Hypothesis; There is no significance difference between the proportions of non participating athletes in 1999 and 2000
[tex]H_0:(p_1-p_2)\neq 0[/tex]
Alternative Hypothesis: The proportion of non participating athletes in 2000 will be more than the proportion of non participating athletes in 1999
[tex]H_1:(p_1-p_2)<0[/tex]
The proportion of nonparticipating athletes in 1999 is given by
[tex]\hat p_1 = \frac{x_1}{n_1} \\\\=\frac{159}{830} =0.1916[/tex]
The proportion of nonparticipating athletes in 2000 is given by
[tex]\hat p_2 =\frac{x_2}{n_1} \\\\=\frac{133}{825} =0.1612[/tex]
The pooled proportion can be calculated using the following formula
[tex]\hat p = \frac{x_1+x_2}{n_1+n_2} \\\\=\frac{159+133}{830+825} =0.1764[/tex]
under the null hypothesis, the test statistics can be calculated as follows
[tex]Z=\frac{\hat p_1 - \hat p_2}{\sqrt{\hat p \hat q(\frac{1}{n_1}+\frac{1}{n_2} ) } }[/tex]
[tex]=\frac{0.1916-0.1612}{\sqrt{(0.1764)(0.8236)(\frac{1}{830} +\frac{1}{825} )} } \\\\=1.6257[/tex]
Determine the P-value using the following formula
P-value = Normdist(1.6257)
=0.947993
Here, it can be observed that the P-value is greater than the level of the significance,
Hence, the null hypothesis fails to be rejected
Therefore it can be concluded that there is insufficient evidence to support that the proportions of non participating athletes in 2000 will be more than the proportions of non participating athletes in 1999
Rebecca Pearson is a widow and needs to take care of the expenses in her household. Her budget is below.
Find her net monthly cash flow. (Assume 1 month = 4 weeks)
Income Expenses
Salary: $2300/month
Rent: $1090/month
Groceries: $200/week
Utilities: $125/month
Car Insurance: $525 semiannually
Gasoline: $25/week
Miscellaneous: $200/month
Phone: $50/month
Hey there!
First, let's take all of the expenses and change the ones that aren't monthly into monthly.
Groceries: $800/month
Car insurance: $87.5/month
Gasoline: $100/month
Now, let's add together all of our expenses
1090+800+125+87.5+100+200+50=2452.5
Now, we subtract that from her salary.
2300-2452.5=-152.5
Therefore, Rebecca's net monthly cash flow is -$152.5. She should spend a bit less on groceries, not do so much miscellaneous, find a place that charges less rent, drive less, etc. so she isn't spending more than she earns.
I hope that this helps! Have a wonderful day!
Which undefined term is used to define an angle
Answer:
The undefined term which is used to define an angle is line i.e., . Further explanation: In geometry the three terms which are considered to be undefined are line, point and plane.
Answer:
Line
Step-by-step explanation:
A line is a undefined term used to define a angle. An angle is the corner that is created where two non-parallel lines meet/ intersect
Using a 40% solution, make 100 mL of a 10% solution?
Answer:
I don't know
Step-by-step explanation:
but that looks like chemistry not biology
Kimberly goes on a road trip; her car gets 25 miles per gallon (mpg) and gas costs $3.24 per gallon. Let n represent the number of miles Kimberly has traveled since she started driving.
a. Suppose Kimberly has traveled 252 miles (n 252) since she started driving. i. How many gallons of gasoline has she used since she started driving? gallons Preview i. What is the cost of the gasoline that she has used since she started driving?
b. Write an expression in terms of n that represents the number of gallons of gasoline she has used since she started driving.
c. Write an expression in terms of n that represents the cost of the gasoline that she has used since she started driving.
Answer:
a) 10.08 gallons and $32.66 of gas
b) gallons used = n/25
c)cost of the gasoline = [tex]\frac{n}{25}(3.24)[/tex]
Step-by-step explanation:
a) We know that Kimberly has traveled 252 miles and we also know that her car gets 25 miles per gallon. We can apply proportions and rule of three:
25 miles ------ 1 gallon
252 miles ----- x gallons
Solving for x:
x gallons = 252 miles(1 gallon)/25 miles= 10.08 gallons.
Thus, she has used 10.08 gallons since she started driving.
Now we need to know the cost of the gasoline that she has used.
We know that each gallon of gas costs $3.24 and she has used 10.08 gallons. Again, we can apply proportions and rule of three:
1 gallon ------ 3.24 dollars
10.08 gallons---- x dollars.
Solving for x we get:
[tex]x=(10.08)(3.24)[/tex]= 32.659=32.66 dollars.
Thus, she has used $32.66 of gas since she started driving.
b) Write an expression in terms of n that represents the number of gallons of gasoline she has used since she started driving.
If we know that n is the number of miles that she drives, from what we wrote above, an expression to know the number of gallons she has used would be:
Gallons used = n/25 (since her car gets 25 miles per gallon) where n is the number of miles.
c) Write an expression in terms of n that represents the cost of the gasoline that she has used since she started driving.
Again, to know the cost of the gasoline we first need to know how many gallons she has used. From b) we know that the expression to know how many gallons she has used is n/25. Since each gallon costs $3.24 we will multiply this number by n/25 and we will get the cost (like we did in a))
Therefore, the cost of the gasoline = [tex]\frac{n}{25}(3.24)[/tex] where n is the number of miles.
What is the average rate of change of f over the interval [-1, 4] Give an exact number.
Answer:
1.4
Step-by-step explanation:
The average rate of change is the "rise" divided by the "run".
rise/run = (f(4) -f(-1))/(4 -(-1)) = (0 -(-7))/(4+1)
rise/run = 7/5 = 1.4
The average rate of change on the interval [-1. 4] is 1.4.
We will see that the average rate of change in the given interval is 1.4
How to find the average rate of change?
For a given function f(x), the average rate of change on an interval [a, b] is given by:
[tex]r = \frac{f(b) - f(a)}{b - a}[/tex]
In this case the interval is [-1, 4], using the graph we can see that:
f(-1) = -7
f(4) = 0
replacing that in the formula we get:
[tex]r = \frac{0 - (-7)}{4 - (-1)} = \frac{7}{5} = 1.4[/tex]
If you want to learn more about rates of change, you can read:
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To ______ a function, you need to stretch or compress it
Answer: It’s to change the shape of a function
Step-by-step explanation:
To change the shape of a function, you need to stretch or compress it.
How to stretch or compress a function?In math terms, you can stretch or compress a function horizontally by multiplying x by some number before any other operations. To stretch the function, multiply by a fraction between 0 and 1. To compress the function, multiply by some number greater than 1.
Is there a function for every shape?By definition, a function has one possible output for any given input. So if you want your function defined as some y=f(x), then not every shape can be written as a function. Any shape that has two points directly above each other (relative to the x-axis) cannot be written as a function, even a piecewise one.
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Suppose that a researcher is planning a new study on hemoglobin levels amongst women under 25 years old. Previous research suggest that the standard deviation of hemoglobin is 0.7 g/dl. In the new study the research wants to have the standard error for the sample mean to be no more than 0.05 g/dl. Find the required sample size for the new study.
Answer:
A sample size of at least 531 is required.
Step-by-step explanation:
We are lacking the confidence level to solve this question, so i am going to use a 90% confidence level.
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.05 = 0.95[/tex], so [tex]z = 1.645[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Find the required sample size for the new study.
A sample size of at least n is required.
n is found when [tex]M = 0.05[/tex]
We have that [tex]\sigma = 0.7[/tex]
So
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.05 = 1.645*\frac{0.7}{\sqrt{n}}[/tex]
[tex]0.05\sqrt{n} = 1.645*0.7[/tex]
[tex]\sqrt{n} = \frac{1.645*0.7}{0.05}[/tex]
[tex](\sqrt{n})^{2} = (\frac{1.645*0.7}{0.05})^{2}[/tex]
[tex]n = 530.4[/tex]
Rounding up
A sample size of at least 531 is required.
If the size of the sample to be used in a particular test of attributes has not been determined by utilizing statistical concepts, but the sample has been chosen in accordance with random selection procedures
A) No inferences can be drawn from the sample.
B) The auditor has committed a nonsampling error.
C) The auditor may or may not achieve the desired risk of assessing control risk too low.
D) The auditor will have to evaluate the results by reference to the principles of discovery sampling.
E) The auditor may or may not achieve the desired
Answer:
C) The auditor may or may not achieve the desired risk of assessing control risk too low.
Step-by-step explanation:
In a concept of risk sampling, if the sample size is chosen randomly in accordance with random selection procedures, the auditor may or may not achieve the desired risk of assessing risk too low. In other words the auditor may or may not achieve desired precision. This is because a samole chosen randomly may not represent the true population.
This depends largely on the sample size. If the sample size selected is too small, the allowance for sampling risk will be larger than what is required because it will lead to a large standard error of the mean
Suppose a county’s population can be approximated with the function () = 34(1.00804) where is the number of years since 2000, and is measured in millions of citizens.
Answer:
Population = 34.27336
Step-by-step explanation:
Given:
Population function (t) = 34(1.00804)^t
Number of year = 2000
Find:
Number of citizen in year 2000
Computation:
We know that, base year is 2000
So, t = 1
Population function (t) = 34(1.00804)^t
Population function (1) = 34(1.00804)^1
Population = 34(1.00804)
Population = 34.27336
Therefore, Population is 34.273636 million
Will mark brainliest! Thanks ! and like if you can please explain it cuz I want to understand it to :)
Answer: F.) 7 triangles
Step-by-step explanation:
Congruent means completely equal in side lengths and angles. Think of this weird figure like 4 triangles that are see through and are covering a diamond underneath
Of those 4 "see through triangles", there are 3 equal to ΔABC
Now on the diamond underneath, there is another 4. Its hard to actually explain what I mean, but take two triangles from that dimaond. Theyre gonna be congruent to ΔABC.
That's 4 + 3 = 7 total triangles
Which operation is the default operation in algebra?
Step-by-step explanation:
in mathematics, a basic algebra corporation is there any one of the traditional operation of arithmetic, which are addition, subtraction, multiply, division, rising to an integer power, and taking root (fractional power ).
average of a data set was 40, and that standard deviation was 10, what else could you derive from that information.
Answer:
[tex] \bar x = 40, s =10[/tex]
And from these values we can estimate the sample variance like this:
[tex] s^2 = 10^2 =100[/tex]
And we can also estimate the coeffcient of variation given by:
[tex] \hat{CV} =\frac{s}{\bar x}[/tex]
And replacing we got:
[tex] \hat{CV} = \frac{10}{40}= 0.25[/tex]
And this coefficient is useful in order to see the variability in terms of the mean for this case since is lower than 1 we can conclude that this variation around the mean is low.
Step-by-step explanation:
For this case we have the following info given:
[tex] \bar x = 40, s =10[/tex]
And from these values we can estimate the sample variance like this:
[tex] s^2 = 10^2 =100[/tex]
And we can also estimate the coeffcient of variation given by:
[tex] \hat{CV} =\frac{s}{\bar x}[/tex]
And replacing we got:
[tex] \hat{CV} = \frac{10}{40}= 0.25[/tex]
And this coefficient is useful in order to see the variability in terms of the mean for this case since is lower than 1 we can conclude that this variation around the mean is low.