Answer:
A = 19.6 ft²
Step-by-step explanation:
A = πr² Use this equation to find the area of the circle
A = π(2.5)² Multiply
A = π(6.25) Multiply
A = 19.6 ft²
Dora likes to explore. Recently, she explored southeast Australia where she found some very large trees known as Eucalyptus regnans or Mountain Ash. She wondered if they were taller, on average, than the coastal Douglas Firs of her native state of Oregon in the United States, which have an average height of 250 feet in old growth areas. Dora measured the heights of 15 Mountain Ash trees in southeast Australia and found an average height of these trees of 293 feet. Suppose s 25 feet. Assume the heights of the 15 trees in Dora's sample are representative of the heights of all Mountain Ash trees in southeast Australia. The t-statistic for this problem is 6.661. Based on this t-statistic, which of the following is true? Choose the correct answer below.
A. With a p-value of 0.999, there is sufficient evidence to accept the null hypothesis as true.
B. With a p-value less than 0.0001, there is not sufficient evidence to reject the null hypothesis and accept the alternative as true. y
C. With a p-value less than 0.0001, there is sufficient evidence to reject the null hypothesis and accept the alternative as true.
D. With a p-value less than 0.0001, there is not sufficient evidence to accept the null hypothesis as true. 0 E. With a p-value of 0.999, there is not sufficient evidence to reject the null hypothesis and accept the alternative as true.
Answer:
C. With a p-value less than 0.0001, there is sufficient evidence to reject the null hypothesis and accept the alternative as true.
Step-by-step explanation:
She performed an hypothesis test with the sample of size n=15 that she takes. The t-statistic has a value of 6.661.
The degrees of freedom for this sample size are:
[tex]df=n-1=15-1=14[/tex]
The P-value for a statistic t=6.661 and 14 degrees of freedom is:
[tex]\text{P-value}=P(t>6.661)=0.00001[/tex]
With these P-value we know that the effect is significant and the null hypothesis is rejected. There is enough evidence to support the claim that the mean height of Mountain Ash trees is greater than the coastal Douglas Firs.
A research company desires to know the mean consumption of meat per week among people over age 27. A sample of 1179 people over age 27 was drawn and the mean meat consumption was 1.5 pounds. Assume that the population standard deviation is known to be 1.2 pounds. Construct the 99% confidence interval for the mean consumption of meat among people over age 27. Round your answers to one decimal place.
Answer:
The 99% confidence interval for the mean consumption of meat among people over age 27 is between 1.4 pounds and 1.6 pounds.
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.
[tex]M = 2.575*\frac{1.2}{\sqrt{1179}} = 0.1[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 1.5 - 0.1 = 1.4 pounds
The upper end of the interval is the sample mean added to M. So it is 1.5 + 0.1 = 1.6 pounds
The 99% confidence interval for the mean consumption of meat among people over age 27 is between 1.4 pounds and 1.6 pounds.
A gun mass of 5 kg fired a bullet of mass 10 g with the velocity of 360 km/h. What
is gun’s velocity of pushing behind?
answer fast please
Answer:
The recoil velocity of the gun is [tex]0.72\,\,\frac{km}{h}[/tex] and is pointing in opposite direction to the velocity of the bullet.
Step-by-step explanation:
Use conservation of linear momentum, which states that the momentum of the bullet (product of the bullet's mass times its speed) should equal in absolute value the momentum of the recoiling gun (its mass times its recoil velocity).
We also write the mass of the bullet in the same units as the mass of the gun (for example kilograms). Mass of the bullet = 0.010 kg
In mathematical terms, we have:
[tex]5\, kg * v= 0.01 \,kg\,* 360\,\frac{km}{h} \\v=\frac{0.01\,*360}{5} \,\,\frac{km}{h}\\v=0.72\,\,\frac{km}{h}[/tex]
Please answer this correctly
Answer:
20-39 => 2
40-59 => 1
60-79 => 1
80-99 => 6
100-119 => 5
Answer: 2, 1, 1, 6, 5
Step-by-step explanation:
20-39
2 | 3
3 | 9
40-59
5 | 0
60-79
7 | 5
80-99
8 | 1 2 4
9 | 3 9 9
100-119
10 | 1 1 5 6
11 | 1
What are the solutions to the quadratic equation 2x^2 + 10x - 48 = 0?
A. x= -4 and x = 6
B. X= -8 and x = 2
c. x= -6 and x = 8
D. X = -8 and x = 3
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions. CHECK ALL THAT APPLY.
Answer:
B, E
Step-by-step explanation:
A line has a negative slope when it decreases going left to right.
As the absolute value of the slope gets larger (-2 to -3 would be 2 to 3), the graph gets steeper (-3 is steeper than -2).
Answer:
B & E
Step-by-step explanation:
If a line crosses the y-axis at (0,1) and has a slope of 4/5 what is the equation of the line
Answer:
y = 4/5x + 1
Step-by-step explanation:
y = mx + b
m = slope
b = y-intercept
y = 4/5x + 1
Answer:4y-5x=5
Step-by-step explanation:
3y-y please can you work it out
What is the value of m squared minus 2 m n + n squared for m = negative 2 and n = 4?
-4-2×-2×64
-4+4×64
-4+256
=252
Answer: (36)
hope this helps you have a wonderful day
Step-by-step explanation:
Show all work to solve the equation for x. If a solution is extraneous, be sure to identify it. Square root of the quantity x + 6 end quantity - 4 = x.
Answer:
x = 2 is the solution of the given equation
Step-by-step explanation:
Step(i):-
Given equation
[tex]\sqrt{x+6-4} = x[/tex]
squaring on both sides , we get
[tex](\sqrt{x+2})^{2} = x^{2}[/tex]
⇒ x + 2 = x²
⇒x² - x -2 =0
Step(ii):-
Given x² - x -2 =0
⇒ x² - 2x + x - 2 =0
⇒ x ( x-2) + 1(x - 2) =0
⇒ (x + 1) ( x-2) =0
⇒ x = -1 and x =2
x = 2 is the solution of the given equation
Verification:-
[tex]\sqrt{x+6-4} = x[/tex]
Put x= 2
[tex]\sqrt{2+6-4} = 2[/tex]
[tex]\sqrt{4} = 2[/tex]
2 = 2
It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological sites tend to lose their cultural identity and specific cultural affiliation as the elevation of the site increases. Let x be the elevation (in thousands of feet) of an archaeological site in the southwestern United States. Let y be the percentage of unidentified artifacts (no specific cultural affiliation) at a given elevation. The following data were obtained for a collection of archaeological sites in New Mexico. x = 5.22 5.69 6.25 6.75 7.25 y 17 12 33 37 62What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? a. 95.7% b. 0.7% c. 8.4% d. 91.6% e. 4.3%
Answer:
(B) 0.7%
Step-by-step explanation:
X = Land Elevation (in ,000 feet)
Y = Unidentified Artifacts (in %)
The hypothetical theory says that:
The higher the elevation, the higher the percentage of unidentified artifacts in the location.
To find the percentage of variation in Y that can be explained by variations in X, we find the slope of the graph of X on Y.
Transforming X to thousand feets, we have 5220, 5690, 6250, 6750, 7250. This is in the attachment, plotted against 17, 12, 33, 37 and 62 respectively.
Further calculations, along with the graph, are in the attachment below. The answer therein is (B) 0.7%
What is the slope of line p?
ty
4
DONE
===========================================================
Explanation:
Start at the point (0,0) which is the origin. Move up 2 units then to the right 3 units to arrive at the next blue point (3,2). We see that
rise = 2
run = 3
slope = rise/run = 2/3
----------
If you want to use the slope formula, then you would say
m = (y2 - y1)/(x2 - x1)
m = (2 - 0)/(3 - 0)
m = 2/3
I used the two points (0,0) and (3,2). You could use any two points you like on this line.
Side note: The slope is positive because we are moving uphill as you move from left to right along this orange line.
The slope of the line p is given by 2/3.
What is Slope of a Straight line?The tangent value of the angle which the straight line makes with the positive X axis is called the slope of that particular straight line.
If s line passes through two points (a,b) and (c,d) then the slope of the line (m) is given by,
m = (d-b)/(c-a)
Here in the given figure we can see that the given line p passes through (3,2), (-3,-2) and the origin (0,0)
then taking any two points out of that three (3,2), (0,0) we get, the slope of p is given by,
m = (2-0)/(3-0) = 2/3
Hence slope of line p is given by 2/3.
Learn more about Slope here -
https://brainly.com/question/3493733
#SPJ2
In a sample of real estate ads, 62% of homes for sale have garages, 19% have swimming pools, and 15% have both features. What is the probability that a home for sale has a pool, a garage or both? State your answer as a decimal, not as a percent.
Answer:
66%
Step-by-step explanation:
15% of homes have both features.
The percentage of homes that have a pool and no garage is:
Pool only = 19% - 15% = 4%
The percentage of homes that have a garage and no pool is:
Garage only = 62% - 15% = 47%
Therefore, the percentage of homes that have a pool, a garage or both is:
[tex]P = 4\%+47\%+15\%\\P=66\%[/tex]
g A psychic was tested for extrasensory perception (ESP). The psychic was presented with cards face down and asked to determine if each of the cards was one of four symbols: a star, cross, circle, or square. Let p represent the probability that the psychic correctly identified the symbols on the cards in a random trial. How large a sample n would you need to estimate p with margin of error 0.01 and 95% confidence?
Answer:
Step-by-step explanation:
Hello!
The objective is to test ESP, for this, a psychic was presented with cards face down and asked to determine if each of the cards was one of four symbols: a star, cross, circle, square.
Be X: number of times the psychic identifies the symbols on the cards correctly is a size n sample.
p the probability that the psychic identified the symbol on the cards correctly
You have to calculate the sample size n to estimate the proportion with a confidence level of 95% and a margin of error of d=0.01
The CI for the population proportion is constructed "sample proportion" ± "margin of error" Symbolically:
p' ± [tex]Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex]
Where [tex]d= Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex] is the margin of error. As you can see, the formula contains the sample proportion (it is normally symbolized p-hat, in this explanation I'll continue to symbolize it p'), you have to do the following consideration:
Every time the psychic has to identify a card he can make two choices:
"Success" he identifies the card correctly
"Failure" he does not identify the card correctly
If we assume that each symbol has the same probability of being chosen at random P(star)=P(cross)=P(circle)=P(square)= 1/4= 0.25
Let's say, for example, that the card has the star symbol.
The probability of identifying it correctly will be P(success)= P(star)= 1/4= 0.25
And the probability of not identifying it correctly will be P(failure)= P(cross) + P(circle) + P(square)= 1/4 + 1/4 + 1/4= 3/4= 0.75
So for this experiment, we'll assume the "worst case scenario" and use p'= 1/4 as the estimated probability of the psychic identifying the symbol on the card correctly.
The value of Z will be [tex]Z_{1-\alpha /2}= Z_{0.975}= 1.96[/tex]
Now using the formula you have to clear the sample size:
[tex]d= Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex]
[tex]\frac{d}{Z_{1-\alpha /2}} = \sqrt{\frac{p'(1-p')}{n} }[/tex]
[tex](\frac{d}{Z_{1-\alpha /2}})^2 =\frac{p'(1-p')}{n}[/tex]
[tex]n*(\frac{d}{Z_{1-\alpha /2}})^2 = p'(1-p')[/tex]
[tex]n = p'(1-p')*(\frac{Z_{1-\alpha /2}}{d})^2[/tex]
[tex]n = (0.25*0.75)*(\frac{1.96}{0.01})^2= 7203[/tex]
To estimate p with a margin of error of 0.01 and a 95% confidence level you have to take a sample of 7203 cards.
I hope this helps!
Answer:
The sample size should be 6157
Step-by-step explanation:
Given that the margin of error (e) = ± 0.01 and the confidence (C) = 95% = 0.95.
Let us assume that the guess p = 0.25 as the value of p.
α = 1 - C = 1 - 0.95 = 0.05
[tex]\frac{\alpha }{2} =\frac{0.05}{2}=0.025[/tex]
The Z score of α/2 is the same as the z score of 0.475 (0.5 - 0.025) which is 1.96. Therefore [tex]Z_\frac{\alpha }{2}=Z_{0.025}=1.96[/tex]
To determine the sample size n, we use the formula:
[tex]Z_{0.025}*\sqrt{\frac{p(1-p)}{n} }\leq e\\Substituting:\\1.96*\sqrt{\frac{0.2(1-0.2)}{n} } \leq 0.01\\\sqrt{\frac{0.2(0.8)}{n} }\leq \frac{1}{196}\\\sqrt{0.16} *196 \leq \sqrt{n}\\78.4\leq \sqrt{n}\\ 6146.56\leq n\\n=6157[/tex]
riley has a farm on a rectangular piece of land that is 200 meters wide
Answer:
Do you mean "Riley has a farm on a rectangular piece of land that is 200 meters wide. This area is divided into two parts: A square area where she grows avocados (whose side is the same as the length of the farm), and the remaining area where she lives.
Every week, Riley spends $3 per square meter on the area where she lives, and earns $7 per square meter from the area where she grows avocados. That way, she manages to save some money every week." ?
The answer is 7L^2>3l(200-l)
URGENT!! EASY IM DUMB MY LAST QUESTION WILL FOREVER BE GRATEFUL PLS HELP WILL GIVE BRANLIEST!! AT LEAST TAKE A LOOK!!!! PLS I AM BEGGING!!!
18. Using the diagram below as reference, write a paragraph proof to prove that the symmetric property of congruence exists for any two angles. (IMAGE BELOW)
Given: ∠A is congruent to ∠B
Prove: ∠B is congruent to ∠A
Plan: Show that ∠A and ∠B have the same measure, thus ∠B and ∠A have the same measure under symmetry for equality. Conclude with ∠B being congruent to ∠A.
Answer:
Below.
Step-by-step explanation:
18. Since A is congruent to B, you can conclude that B is congruent to A by the Reflexive Property of Congruence.
if you’re good with probability in math 30 please help and answer the question below!!
A six-sided number cube has faces with the numbers 1 through 6 marked on it. What is the probability that a number less than 3 will occur on one toss of the number cube?
a) 1/6
b) 1/2
c) 1/3
d) 2/3
Answer: b) 1/3
Step-by-step explanation:
The numbers LESS THAN 3: 1, 2
[tex]\dfrac{\text{Quantity of numbers less than 3}}{Total\ number}\quad =\dfrac{2}{6}\quad \rightarrow \large\boxed{\dfrac{1}{3}}[/tex]
What is the formula to find the area of parallelogram
Step-by-step explanation:
area of parallelogram= height * length of base
Express 1.8meter in seconds given answer in scientific notation
Answer:
Dear user,
Answer to your query is provided below
Scientific notation = 1.8x10^0
Step-by-step explanation:
This is usually expressed simply as 1.8 (Recall that 10^0 = 1.)
1.8×10^0
Hue wants to buy two necklaces, one for her sister and one for herself. The necklace for her sister costs $43.25, and the necklace for herself costs $26.25. The sales tax on the purchases is 3%. Find the total cost of Hue's purchases, including sales tax.
Answer:
$71.59
Step-by-step explanation:
43.25+26.25
=69.5
69.5×103/100
=71.585
To solve VX +VX-5 = 5 for x, begin with which of these steps?
Answer:
x = 5/v
Step-by-step explanation:
Solve for x:
2 v x - 5 = 5
Add 5 to both sides:
2 v x = 10
Divide both sides by 2 v:
Answer: x = 5/v
Answer:
I'd say start with "Add 5 to both sides"
Step-by-step explanation:
VX +VX-5 = 5
Add 5 to both sides
2VX=10
Divide both sides by 2
VX=5
Divide both sides by V
X=[tex]\frac{5}{V}[/tex]
The population P of a culture of Pseudomonas aeruginosa bacteria is given by P = −1718t2 + 82,000t + 10,000, where t is the time in hours since the culture was started. Determine the time(s) at which the population was 600,000. Round to the nearest hour.
Answer:
Rounding to the nearest hour, the times at which the population was 600,000 was at 9 hours and at 39 hours.
Step-by-step explanation:
Determine the time(s) at which the population was 600,000.
This is t for which P(t) = 600000. To do this, we solve a quadratic equation.
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\bigtriangleup}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\bigtriangleup}}{2*a}[/tex]
[tex]\bigtriangleup = b^{2} - 4ac[/tex]
In this question:
[tex]P(t) = -1718t^{2} + 82000t + 10000[/tex]
We have to find t for which P(t) = 600000. Then
[tex]600000 = -1718t^{2} + 82000t + 10000[/tex]
[tex]-1718t^{2} + 82000t - 590000 = 0[/tex]
So [tex]a = -1718, b = 82000, c = -590000[/tex]
Then
[tex]\bigtriangleup = 82000^{2} - 4*(-1718)*(-590000) = 2669520000[/tex]
[tex]t_{1} = \frac{-82000 + \sqrt{2669520000}}{2*(-1718)} = 8.8[/tex]
[tex]t_{2} = \frac{-82000 - \sqrt{2669520000}}{2*(-1718)} = 38.9[/tex]
Rounding to the nearest hour, the times at which the population was 600,000 was at 9 hours and at 39 hours.
Isaac is a professional swimmer who trains, in part, by running. She would like to
estimate the average number of miles she runs in each week. For a random sample
of 20 weeks, the mean is
x
= 17.5 miles with standard deviation s = 3.8 miles. Find
a 99% confidence interval for the population mean number of weekly miles Isaac runs.
(a) 15.01 to 19.99 miles (b) 15.07 to 19.93 miles
(c) 15.34 to 19.66 miles (d) 15.31 to 19.69 miles
(e) 15.08 to 19.92 miles
Answer: (b) 15.07 to 19.93 miles
Step-by-step explanation:
Confidence interval is written in the form,
(Sample mean - margin of error, sample mean + margin of error)
The sample mean, x is the point estimate for the population mean.
Margin of error = z × s/√n
Where
s = sample standard deviation = 3.8
n = number of samples = 20
From the information given, the population standard deviation is unknown and the sample size is small, hence, we would use the t distribution to find the z score
In order to use the t distribution, we would determine the degree of freedom, df for the sample.
df = n - 1 = 20 - 1 = 19
Since confidence level = 99% = 0.99, α = 1 - CL = 1 – 0.99 = 0.01
α/2 = 0.02/2 = 0.005
the area to the right of z0.005 is 0.025 and the area to the left of z0.025 is 1 - 0.005 = 0.995
Looking at the t distribution table,
z = 2.861
Margin of error = 2.861 × 3.8/√20
= 2.43
the lower limit of this confidence interval is
17.5 - 2.43 = 15.07 miles
the upper limit of this confidence interval is
17.5 + 2.43 = 19.93 miles
Jamie needs the following items from the hardware store a drill bit that cost 4.99 nails that caused 0.46 and sandpaper that cost 0.89 how much money was spent if the sales tax rate is 6%
Answer: $5.96
Step-by-step explanation:
4.99 + 0.46 + 0.89 is what she paid, not with tax. That equals 6.34.
Applying 6% means we calculate 6% of 6.34 and then subtract it from 6.34. (Or, we can also calculate 100-6%=94% of 6.34). Either way, the answer is 5.9596, or rounded, 5.96.
Hope that helped,
-sirswagger21
You are a medical assistant in a pediatrician’s office and one of your responsibilities is evaluating the growth of newborns and infants. Your first patient, a baby girl named Ivy Smith, was 21.5 inches long at 3 months old. At 8 months, you measure her at 24 inches long. For your medical records, all measurements must be given both in inches and in centimeters: 1 inch = 2.54 cm
I need to come up with an equation for this.
Please answer this correctly
Answer:
3 3/5 hours.
Step-by-step explanation:
There are 3 students who logged 1 1/5 so:
[tex]1\frac{1}{5} +1\frac{1}{5} +1\frac{1}{5} =3\frac{3}{5}[/tex]
3 3/5 hours have been logged total by those who logged 1 1/5 hours.
Suppose 90 geology students measure the mass of an ore sample. Due to human error and limitations in the reliability of the​ balance, not all the readings are equal. The results are found to closely approximate a normal​ curve, with mean 88 g and standard deviation 1 g. Use the symmetry of the normal curve and the empirical rule as needed to estimate the number of students reporting readings between 87 g and 89 g.The number of students reporting readings between 87 g and 89 g is:________
Answer:
The number of students reporting readings between 87 g and 89 g is 61
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 88g
Standard deviation = 1g
Percentage of students reporting readings between 87 g and 89 g
87 = 88-1
So 87 is one standard deviation below the mean.
89 = 88+1
So 89 is one standard deviation above the mean.
By the Empirical Rule, 68% of students are reporting readings between 87 g and 89 g.
Out of 90 students:
0.68*90 = 61.2
Rounding to the nearest whole number:
The number of students reporting readings between 87 g and 89 g is 61
Which table represents a relation that is not function
Please urgent
Translate the phrase into a variable expression. Use the letter d to name the variable. If necessary use the asterisk for multiplication and the slash for division. the product of 40 and distance to the finish line
Answer:
40*d
Step-by-step explanation:
The word product means multiplication, and here it is multiplying 40 and the distance(d).
Answer:
40x5
Step-by-step explanation:
What is the area of the circle?
Answer:
A =50.24 in ^2
Step-by-step explanation:
The diameter is 8 inches
The radius is 1/2 diameter
r = d/2 = 8/2 = 4
The area of the circle is given by
A = pi r^2
A = 3.14 (4)^2
A =50.24 in ^2
Answer:
C. 50.24 in²
Step-by-step explanation:
d= 8 in
r= 8/2= 4 in
Area= πr²= 3.14×4²= 50.24 in²