Answer:
9/25
Step-by-step explanation:
Don't worry, I just took this test and got it correct. Best of luck to you all!
If a random sample of 53 students was asked for the number of semester hours they are taking this semester. The sample standard deviation was found to be s = 4.7 semester hours. How many more students should be included in the sample to be 99% sure that the sample mean x is within 1 semester hour of the population mean for all students at this college?
Answer:
94 more students should be included in the sample.
Step-by-step explanation:
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{1-0.99}{2} = 0.005[/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]1-0.005 = 0.995[/tex], so [tex]z = 2.575[/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.
How many students we need to sample to be 99% sure that the sample mean x is within 1 semester hour of the population mean?
We need to survey n students.
n is found when M = 1.
We have that [tex]\sigma = 4.7[/tex]
So
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
[tex]1 = 2.575*\frac{4.7}{\sqrt{n}}[/tex]
[tex]\sqrt{n} = 2.575*4.7[/tex]
[tex](\sqrt{n})^{2} = (2.575*4.7)^{2}[/tex]
[tex]n = 146.47[/tex]
Rounding up
147 students need to be surveyed.
How many more students should be included...?
53 have already been surveyed
147 - 53 = 94
94 more students should be included in the sample.
Does a point have a one dimension length
Answer:
No.
Step-by-step explanation:
A point has no length, height or depth. It only has position.
A line has one dimensional length.
1. If the ratio of the ages of Kissi and Esinam is 3:5 and that of Esinam and Lariba is 3:5 and
the sum of the ages of all 3 is 147 years, what is the age difference between oldest the
youngest?
Ans: years
2. The HCF of two numbers is 11, and their L.C.M is 368. If one number is 64, then the other
number is ….
Answer:
1) 48 years.
2) Question incorrect.
11 isn't a factor of 64, and 368 isn't a multiple of 64. 11 also isn't a factor of 368, hence, it would be impossible to find the unknown second number with all of these false information in the question.
Step-by-step explanation:
Let the ages of Kissi, Esinam and Lariba be x, y and z respectively.
Ratio of the ages of Kissi and Esinam is 3:5
x:y = 3:5
(x/y) = (3/5)
5x = 3y
x = (3y/5) (eqn 1)
Ratio of the ages of Esinam and Lariba is 3:5
y:z = 3:5
(y/z) = (3/5)
5y = 3z
z = (5y/3) (eqn 2)
The sum of their 3 ages is 147
x + y + z = 147 (eqn 3)
Substituting the values of x and z from eqn 1 and 2 into eqn 3, we have
(3y/5) + y + (5y/3) = 147
(49y/15) = 147
y = (147×15/49) = 45.
x = (3y/5) = (3×45/5) = 27
z = (5y/3) = (5×45/3) = 75
The ages of Kissi, Esinam and Lariba are then 27, 45 and 75 respectively.
The difference in the ages of the oldest amf the youngest is thus, 75 - 27 = 48 years.
2) This question seems to be faulty and incorrect as 11 isn't a factor of 64, and 368 isn't a multiple of 64. 11 also isn't a factor of 368, hence, it would be impossible to find the unknown second number with all of these false information in the question.
Hope this Helps!!!
The mass of the Eiffel Tower is about 9.16 ⋅ 10^6 kilograms. The mass of the Golden Gate Bridge is 8.05 ⋅ 10^8 kilograms. Approximately how many more kilograms is the mass of the Golden Gate Bridge than the mass of the Eiffel Tower? Show your work and write your answer in scientific notation.
Answer:
[tex]7.9584 \times 10^8[/tex]
Step-by-step explanation:
[tex]8.05 \times 10^8 - 9.16 \times 10^6[/tex]
[tex]805000000-9160000[/tex]
[tex]=795840000[/tex]
The number of pieces of popcorn in a large movie theatre popcorn bucket is normally distributed, with a mean of 1610 and a standard deviation of 10. Approximately what percentage of buckets contain between 1600 and 1620 pieces of popcorn?
Answer:
A
Step-by-step explanation:
We know that in normal distribution, approximately 34% of bags will fall with in one standard deviation on one side. On both sides within the range of 1 standard deviation, 34 + 34 = 68 % of bags will fall.
Our range is:
1600 to 1620
1610 - 10 to 1610 + 10
So the answer is 1
That means, that 68% is the answer.
Answer:
The answer is A.
Step-by-step explanation:
Approximately 68%
A large car insurance company selected samples of single and married male policyholders and recorded the number who made an insurance claim over the preceding three-year period. Single Policyholders Married Policyholders n1 = 450 n2 = 925 # making claim = 67 # making claim = 93 Using alpha = 0.05, determine whether the claim rates are higher for single male policyholders verses married male policyholders. Solve using the p-value approach only.
Answer:
The null hypothesis is rejected.
There is enough evidence to support the claim that rates are higher for single male policyholders verses married male policyholders (P-value = 0.004).
Step-by-step explanation:
This is a hypothesis test for the difference between proportions.
The claim is that rates are higher for single male policyholders verses married male policyholders.
Then, the null and alternative hypothesis are:
[tex]H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0[/tex]
The significance level is 0.05.
The sample 1 (single group), of size n1=450 has a proportion of p1=0.1489.
[tex]p_1=X_1/n_1=67/450=0.1489[/tex]
The sample 2 (married group), of size n2=925 has a proportion of p2=0.1005.
[tex]p_2=X_2/n_2=93/925=0.1005[/tex]
The difference between proportions is (p1-p2)=0.0483.
[tex]p_d=p_1-p_2=0.1489-0.1005=0.0483[/tex]
The pooled proportion, needed to calculate the standard error, is:
[tex]p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{67.005+93}{450+925}=\dfrac{160}{1375}=0.1164[/tex]
The estimated standard error of the difference between means is computed using the formula:
[tex]s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.1164*0.8836}{450}+\dfrac{0.1164*0.8836}{925}}\\\\\\s_{p1-p2}=\sqrt{0.0002+0.0001}=\sqrt{0.0003}=0.0184[/tex]
Then, we can calculate the z-statistic as:
[tex]z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.0483-0}{0.0184}=\dfrac{0.0483}{0.0184}=2.62[/tex]
This test is a right-tailed test, so the P-value for this test is calculated as (using a z-table):
[tex]P-value=P(z>2.62)=0.004[/tex]
As the P-value (0.004) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
There is enough evidence to support the claim that rates are higher for single male policyholders verses married male policyholders.
find the slope of the line (-5,2) and (4,2)
Answer:
The answer is 0
Step-by-step explanation:
What is the value of log625^5 converted to a fraction
Answer:
1/4
Step-by-step explanation:
625^x = 5
x = 1/4
Suppose you would like to save P9000 invested at 8% compounded quarterly for 5 years and 6 months. (Note: Round off your answer to the nearest hundredth) (a) How much would the value of her savings at the end of the term? Answer (b) How much is the interest earned by your savings? Answer
Answer:
a) 13913
b) 4913.82
Step-by-step explanation:
The compound interest formula is given by:
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
In this question:
Investment of 9000, so [tex]P = 9000[/tex]
Interest rate of 8%, so [tex]r = 0.08[/tex]
Compounded quarterly, so [tex]n = 4[/tex]
5 years and 6 months, that is, 5 years and half, so [tex]t = 5.5[/tex]
(a) How much would the value of her savings at the end of the term?
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
[tex]A(5.5) = 9000(1 + \frac{0.08}{4})^{4*5.5} = 13913.82[/tex]
(b) How much is the interest earned by your savings?
The amount subtracted by the principal. So
13913.82 - 9000 = 4913.82
Your friend believes that he has found a route to work that would make your commute faster than what it currently is under similar conditions. Suppose that data were collected for a random set of 7 days, where each difference is calculated by subtracting the time taken on the current route from the time taken on the new route. Assume that the populations are normally distributed. Your friend uses the alternative hypothesis Ha:μd<0. Suppose the test statistic t is computed as t≈−3.201, which has 6 degrees of freedom. What range contains the p-value?
Answer:
The range of p-values
0.01 < p < 0.025
Step-by-step explanation:
Explanation:-
Given random sample size 'n' = 7
Assume that the populations are normally distributed
Null Hypothesis :H₀:μd=0.
Alternative Hypothesis:H₁:μd<0.
Degrees of freedom
ν = n-1 =7-1 =6
given the test statistic t = - 3.201
we will use single tailed test in t-distribution table
The test statistic t= 3.201 is lies between the critical values is 0.01 and 0.025
The range of p-values
0.01 < p < 0.025 (check t- distribution table single tailed test)
Final answer:-
The range of p-values
0.01 < p < 0.025
If the probability of a machine producing a defective part is 0.05, what is the probability of
finding exactly 5 defective parts from a sample of 100? (Assume that the process follows a
binomial distribution and round answer to four places)
Answer:
0.1800 to 4 places of decimals.
Step-by-step explanation:
Using the Binomial formula
Probability = 10C5* (0.95)^95 * (0.05)^5
= 100! / 95!*5! * (0.95)^95 * (0.05)^5
= 0.1800178.
Choose the equation for the graph
below.
a. y =
1
X-2
2
b.y =
x²–4
3
c. y =
x+2
-3
d.y=
e. y =
2x+4
1
x2+2x+1
Answer:
C
Step-by-step explanation:
Plugged into calculator
Vertical asymptotes: x=-2
Horizontal asymptotes: y=0
No oblique asymptotes
Two airplanes leave an airport at the same time, flying in the same direction. One plane is flying at twice the speed of the other. If after 4 hours they are 1800 km apart, find the speed of each plane.
Answer:
One plane has a speed of 450 km/h and the other has a speed of 900 km/h.
Step-by-step explanation:
I am going to say that:
The speed of the first plane is x.
The speed of the second plane is y.
One plane is flying at twice the speed of the other.
I will say that y = 2x. We could also say that x = 2y.
Two airplanes leave an airport at the same time, flying in the same direction
They fly in the same direction, so their relative speed(difference) at the end of each hour is y - x = 2x - x = x.
If after 4 hours they are 1800 km apart, find the speed of each plane
After 1 hour, they will be x km apart. After 4, 1800. So
1 hour - x km apart
4 hours - 1800 km apart
4x = 1800
x = 1800/4
x = 450
2x = 2*450 = 900
One plane has a speed of 450 km/h and the other has a speed of 900 km/h.
The lines shown below are perpendicular if the green line has a slope of 3/4 what is the slopes of the red line?
Answer:
b) -4/3
Step-by-step explanation:
perpendicular lines have slopes that are opposite reciprocals. the opposite of 3/4 is -3/4, and the reciprocal of -3/4 is -4/3. hope this helps!
Answer:
It is -4/3
Step-by-step explanation:
Which equation can be used to solve for b?
B
5 cm
С
10 cm
b
30
A
O tan(30)=5/b
O tan(30)=b/5
O tan(30)=10/b
O tan(30)=b/10
Answer:
The answer is option 1.
Step-by-step explanation:
You have to apply Tangent Rule, tanθ = opposite/adjacent:
[tex] \tan(θ) = \frac{oppo.}{adj.} [/tex]
[tex]let \: oppo. = 5 \\ let \: adj. = b \\ let \: θ = 30[/tex]
[tex] \tan(30) = \frac{5}{b} [/tex]
The correct answer is option (A) tan(30)=5/b
Tangent functionThe tangent function is one of the main six trigonometric functions and is generally written as tan x. It is the ratio of the opposite side and the adjacent side of the angle in consideration in a right-angled triangle.How to solve this problem?The steps are as follow:
The right angle triangle is given whose sides are as follow:AB = 10 cm
BC = 5 cm
AC = b cm
To find the tan(30) we will use following formula:tan(x) = opposite side / adjacent side
tan(30) = BC / AC
tan(30) = 5 / b
So, the correct answer is option (A) tan(30)=5/b
Learn more about Tangent function here:
https://brainly.com/question/6904750
#SPJ2
Which whole number can each term of the equation be multiplied by to eliminate the fractions before solving
Answer:
the least common denominator
Step-by-step explanation:
The least common denominator is that number. It is the least common multiple of the denominator values.
__
Simply multiplying by the product of the denominators will eliminate fractions, but may require reduction of fractions in the answer. If the "fractions" are rational expressions, extraneous solutions may be introduced.
The HCF of two numbers is 11, and their L.C.M is 368. If one number is 64, then the other
number is ….
NEED GEOMETRY HELP ASAP PLEASE (12 POINTS)
Answer:
2 times the square root of 10
Step-by-step explanation:
If you make a right triangle and solve for the hypotenuse (the distance between P1 and P2), you will get 2 times the square root of 10.
Please mark this brainliest.
Answer: [tex]2\sqrt{10}[/tex]
Step-by-step explanation:
if you draw a triangle starting from P1 and go up to the y value of P2, the change in y is equal to 6.
From that point, go to the right until you hit P2 to get a change in x of 2.
Youre basically missing the hypotenuse of this triangle that you drew. Which is where the distance formula is derived from. 6^2 + 2^2 = s^2
You get √40 = s. It appears that they want you to simplify this square root. What are the two greatest numbers that multiply to equal 40 and atleast one of them has a perfect square root? That's 10 and 4. you can perfectly take the square root of 4, so go ahead and do that. Put that 2 outside of the square root. That gives you [tex]2\sqrt{10}[/tex]
An urban economist is curious if the distribution in where Oregon residents live is different today than it was in 1990. She observes that today there are approximately 3,109 thousand residents in NW Oregon, 902 thousand residents in SW Oregon, 244 thousand in Central Oregon, and 102 thousand in Eastern Oregon. She knows that in 1990 the breakdown was as follows:
72.7% NW Oregon, 20.7% SW Oregon, 4.8% Central Oregon, and 2.8% Eastern Oregon.
Can she conclude that the distribution in residence is different today at a 0.05 level of significance?
a) Yes, because the p-value = .0009.
b) No, because the p-value = .0009.
c) Yes, because the p-value = .0172.
d) No, because the p-value = .0172.
Answer:
c) Yes, because the p-value = 0.0172
Step-by-step explanation:
The following table is obtained:
Categories Observed(fo) Expected (fe) (fo-fe)²/fe
NW Oregon 3109 4357*0.727=3167.539 1.082
SW Oregon 902 4357*0.207=901.899 0
Central Oregon 244 4357*0.048=209.136 5.812
Eastern Oregon 102 4357*0.028=121.996 3.277
Sum = 4357 4357 10.171
(1) Null and Alternative Hypotheses
The following null and alternative hypotheses need to be tested:
H0:p1=0.727,p2=0.207,p3=0.048,p4=0.028
Ha: Some of the population proportions differ from the values stated in the null hypothesis
This corresponds to a Chi-Square test for Goodness of Fit.
(2) Rejection Region
Based on the information provided, the significance level is α=0.05, the number of degrees of freedom is df=4−1=3, so then the rejection region for this test is R={χ2:χ2>7.815}.
(3) Test Statistics
The Chi-Squared statistic is computed as follows:
[tex]X^2=\sum^n_{i=1}\frac{(O_i-E_i)^2}{y} \\\\= 1.082+0+5.812 +3.277 = 10.171[/tex]
(4) Decision about the null hypothesis
Since it is observed that
[tex]X^2 = 10.171 > X_c^2 = 7.815[/tex]
it is then concluded that the null hypothesis is rejected.
(5) Conclusion
It is concluded that the null hypothesis H_o is rejected. Therefore, there is enough evidence to claim that some of the population proportions differ from those stated in the null hypothesis, at the α=0.05 significance level.
help asap, will get branliest !!
Answer:
D
Step-by-step explanation:
Lines EF and GH are already parallel. Translating them 2 units to the side without changing how far apart they are vertically means they won't intersect and will remain the same distance apart.
Answer:
D
Step-by-step explanation:
They are parallel lines
Which chart is good for showing the following? For each part, choose the most appropriate chart from the charts listed. - trends over time - cross tabulation - the relationship among 3 quantitative variables - the relationship between 2 quantitative variables - frequency distribution of quantitative data - show differences in numbers across categories A. column or bar chart B. line chart C. heat map D. clustered column or bar chart E. bubble chart F. scatter chart G. histogram
Answer:
Step-by-step explanation:
Trends over time - Line charts
Cross tabulation - column or bar chart
The relationship among 3 quantitative variables - Bubble charts or clusteréd column or bar chart
The relationship between 2 quantitative variables - scatter plot
Frequency distribution of quantitative data - Histogram
Show differences in numbers across categories - Bar chart or column charts.
5. The value of 25sqare -24sqare
Answer:
49
Step-by-step explanation:
25²-24²
625-576
=49
use calculator lah dehh
Find the value of a. a) 15 b) 10 c) 25 d) 20
Answer:
answer d) 20
Step-by-step explanation:
Because the two lines are parallel two by two, the figure is a parallelogram.
In a parallelogram the opposite corners are identical.
Given:
opposite corner1 = 130°
opposite corner2= (6a + 10)°
Because corner1 = corner2 we now have:
(6a + 10) = 130
6a + 0 = 130 -10
6a = 120
a = 20
Which is answer d).
There is a clothing store in Bartlesville. The owner has devised his own method of pricing items. A vest costs $20, socks cost $25, a tie costs $15 and a blouse costs $30. Using the method, how much would underwear cost?
Answer:
25
Step-by-step explanation:
I'm going with $25 since socks should cost as much as underwear, you wear them underneath and they're an essential.
divide the following polynomials ( 9 x 4 + 3 x 3 y − 5 x 2 y 2 + x y 3 ) ÷ ( 3 x 2 + 2 x 2 y − x y 2 )
Answer:
2(-2y+9)/3+y
Step-by-step explanation:
The table below represents the total cost of leasing a car at the end each month.
Month 1 -------- 3 -------- 8 -------- 12
Cost $1,859 --- $2,577 --- $4,372 --- $5,808
Write an equation in slope-intercept form to represent the total cost, y, of leasing a car for x months.
Answer:
y= 359 x+1500
Step-by-step explanation:
find the slope m= (2577-1859)÷(3-1) = 359
y=mx+b
find b : substitute x ,y, and m
get b = 1857 - 359*1 = 1500
Answer:
y= 359 x+1500
Step-by-step explanation:
Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the mean tread life was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires?
Answer:
The best estimate of the mean of the population is 50,000 miles, which is the sample mean.
To make a better inference, we know that the 95% confidence interval for the mean is (49,306; 50,694).
Step-by-step explanation:
The unbiased point estimation for the population mean tread life is the sample mean (50,000 miles), as it is the only information we have.
Although, knowing the standard deviation, we can calculate a confidence interval to make a stronger inference.
We calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=50000.
The sample size is N=100.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
[tex]s_M=\dfrac{s}{\sqrt{N}}=\dfrac{3500}{\sqrt{100}}=\dfrac{3500}{10}=350[/tex]
The degrees of freedom for this sample size are:
[tex]df=n-1=100-1=99[/tex]
The t-value for a 95% confidence interval and 99 degrees of freedom is t=1.98.
The margin of error (MOE) can be calculated as:
[tex]MOE=t\cdot s_M=1.98 \cdot 350=694.48[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M-t \cdot s_M = 50000-694.48=49306\\\\UL=M+t \cdot s_M = 50000+694.48=50694[/tex]
The 95% confidence interval for the mean is (49306, 50694).
Assume that women's heights are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches. If 90 women are randomly selected, find the probability that they have a mean height between 62.9 inches and 64.0 inches.
A. 0.7248
B. 0.0424
C. 0.1739
D. 0.9318
Suppose your total taxable income this year is $75,000 you are taxed a rate of 10 percent on the first 25,000 20 percent on the next 25,000 and 30 percent on the final 25,000 what is your total income tax
what is X:
|4x−1|=3
|x|=−4
Answer:
1
Step-by-step explanation: