Answer:
Since the pvalue of the test is 0.09 > 0.01, we do not reject the null hypothesis that the average size of new homes is of 2400 square feet.
Step-by-step explanation:
Toll Brothers is a luxury home builder that would like to test the hypothesis that the average size of new homes exceeds 2,400 square feet. Test to see if the average size of new homes exceeds 2,400 square feet.
At the null hypothesis, we test if the average is of 2400 square feet, that is:
[tex]H_o: \mu = 2400[/tex]
At the alternate hypothesis, we test if the average is greater than 2400 square feet, that is:
[tex]H_a: \mu > 2400[/tex]
The test statistic is:
Since we have the standard deviation for the sample, we use the t-distribution.
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, s is the standard deviation of the sample and n is the size of the sample.
2400 is tested at the null hypothesis:
This means that [tex]\mu = 2400[/tex]
A random sample of 36 newly constructed homes had an average of 2,510 square feet with a sample standard deviation of 480 square feet.
This means that [tex]n = 36, X = 2510, s = 480[/tex]
Test statistic:
[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]
[tex]t = \frac{2510 - 2400}{\frac{480}{\sqrt{36}}}[/tex]
[tex]t = 1.375[/tex]
Pvalue of the test and decision:
The pvalue of the test is the probability of finding a sample mean of at least 2510, which is the pvalue of t = 1.375 with 36 - 1 = 35 degrees of freedom, using a one-tailed test.
With the help of a calculator, this pvalue is of 0.09
Since the pvalue of the test is 0.09 > 0.01, we do not reject the null hypothesis that the average size of new homes is of 2400 square feet.
-2(t+7)=-4t+12 what is the value of t
9514 1404 393
Answer:
13
Step-by-step explanation:
-2(t +7) = -4t +12
t +7 = 2t -6 . . . . . . . divide by -2
13 = t . . . . . . . . . . . . add 6-t
Can someone help fast please!!!!
Answer:
yes it is
Step-by-step explanation:
How do you know how to set up a equation?
Answer:
Basic Steps to Setting Up Equations
-Determine what the question is asking.
-Write down the relevant information in simple statements.
-Assign symbols to unknown values that need to be found.
-Determine how the statements relate to each other mathematically.
Solving Story Problems
Story problems can contain lots of information, including details that are not necessary to solve the problem. Additionally, the problem may assume general knowledge on the reader's part, and not explain all the information explicitly. Writing that information down in a streamlined form is an efficient way to solve problems.
Step-by-step explanation:
Because of safety considerations, in May 2003 the Federal Aviation Administration (FAA) changed its guidelines for how small commuter airlines must estimate passenger weights. Under the old rule, airlines used 180 pounds as a typical passenger weight (including carry-on luggage) in warm months and 185 pounds as a typical weight in cold months. The Alaska Journal of Commerce (May 25, 2003) reported that Frontier Airlines conducted a study to estimate average passenger plus carry-on weights. They found an average summer weight of 183 pounds and a winter average of 190 pounds. Suppose that each of these estimates was based on a random sample of 100 passengers and that the sample standard deviations were 20 pounds for the summer weights and 23 pounds for the winter weights.
Required:
a. Construct and interpret a 95% confidence interval for the mean summer weight (including carry-on luggage) of Frontier Airlines passengers.
b. Construct and interpret a 95% confidence interval for the mean winter weight (including carry-on luggage) of Frontier Airlines passengers.
c. The new FAA recommendations are 190 pounds for summer and 195 pounds for winter. Comment on these recommendations in light of the confidence interval estimates from Parts (a) and (b).
Answer:
a) The 95% confidence interval for the mean summer weight (including carry-on luggage) of Frontier Airlines passengers is between 179 and 187 pounds. This means that we are 95% sure that the mean summer weight of all Frontier Airlines passengers is between these two values.
b)
The 95% confidence interval for the mean winter weight (including carry-on luggage) of Frontier Airlines passengers is between 185.4 pounds and 194.6 pounds. This means that we are 95% sure that the mean winter weight of all Frontier Airlines passengers is between these two values.
c) They are respected, as the upper bound of both intervals is below the new FAA recommendations.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve these questions.
Question a:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 100 - 1 = 99
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 99 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.9842
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.9842\frac{20}{\sqrt{100}} = 4[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 183 - 4 = 179 pounds.
The upper end of the interval is the sample mean added to M. So it is 183 + 4 = 187 pounds.
The 95% confidence interval for the mean summer weight (including carry-on luggage) of Frontier Airlines passengers is between 179 and 187 pounds. This means that we are 95% sure that the mean summer weight of all Frontier Airlines passengers is between these two values.
Question b:
Critical value is the same(same sample size and confidence level).
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.9842\frac{23}{\sqrt{100}} = 4.6[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 190 - 4.6 = 185.4 pounds.
The upper end of the interval is the sample mean added to M. So it is 190 + 4.6 = 194.6 pounds.
The 95% confidence interval for the mean winter weight (including carry-on luggage) of Frontier Airlines passengers is between 185.4 pounds and 194.6 pounds. This means that we are 95% sure that the mean winter weight of all Frontier Airlines passengers is between these two values.
c. The new FAA recommendations are 190 pounds for summer and 195 pounds for winter. Comment on these recommendations in light of the confidence interval estimates from Parts (a) and (b).
They are respected, as the upper bound of both intervals is below the new FAA recommendations.
Maya is a plumbing engineer who works with Overflo clients on residential plumbing and field draining and irrigation projects. Overflo closely supervises all of its engineers, and dictates their work schedules. Noel works part-time in the evenings cleaning the offices and warehouse. To Noel is Overflo's:_____.
a. employee, agent and independent contractor.
b. employee and agent.
c. agent to Overflo's customers.
d. independent contractor only.
18. The temperature was
40° at noon. At midnight the
temperature was -10°.
Which integer describes the
change in temperature?
Answer:
Step-by-step explanation: Find the number between 40 and -10.
start at 40 and end at -10.
-40=0
0-10=-10
the tempature changed by 50 degrees.
A triangular fence has sides that measure 11 yards, 30 yards, and 35 yards. What is the measure of the greatest angle that is formed? Round to the nearest whole degree.
Answer:
108°
Step-by-step explanation:
[tex]a^{2}[/tex] + [tex]b^{2}[/tex] = [tex]c^{2}[/tex]
[tex]35^{2}[/tex] = [tex]11^{2}[/tex] + [tex]30^{2}[/tex]
[tex]\frac{204}{-660}[/tex] = [tex]\frac{-660 cos}{-660}[/tex]
cos = -0.309
The measure of the greatest angle in the triangular fence is approximately 108.5 degrees. To find the measure of the greatest angle in the triangular fence, you can use the Law of Cosines.
The Law of Cosines states:
[tex]c^2 = a^2 + b^2 - 2ab * cos(C)[/tex]
where c is the side opposite the angle C, and a and b are the other two sides of the triangle.
In this case, the sides of the triangle are:
a = 11 yards
b = 30 yards
c = 35 yards
Now, let's find the measure of angle C (the angle opposite the side with length 35 yards):
[tex]c^2 = a^2 + b^2 - 2ab * cos(C)\\35^2 = 11^2 + 30^2 - 2 * 11 * 30 * cos(C)\\1225 = 121 + 900 - 660 * cos(C)\\1225 = 1021 - 660 * cos(C)\\[/tex]
Now, isolate cos(C) by moving the terms around:
[tex]660 * cos(C) = 1021 - 1225\\660 * cos(C) = -204[/tex]
Now, divide by 660 to find cos(C):
[tex]\cos(C) \approx -0.3091[/tex]
Now, find the measure of angle C by taking the inverse cosine (cos^-1) of -0.3091:
[tex]C \approx cos^-1(-0.3091)\\C \approx 108.5 degrees[/tex] (rounded to one decimal place)
Since this is the angle opposite the side with length 35 yards, it is the greatest angle in the triangle.
So, the measure of the greatest angle in the triangular fence is approximately 108.5 degrees.
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what is the volume of a prism if the width is 8 the height is 6 and the length is 4
Answer: 48
Step-by-step explanation:
V = b x h
V = 8 x 6
V = 48
The college plans to use part of its land for a bicycle park.
The space for the bicycle park is rectangular 18 m by 4.8 m.
A rectangular space is needed for each bicycle.
0.6 m
Diagram not
accurately drawn
2 m
The builders think that 90 bicycles can fit in the bicycle park.
Are the builders correct?
Show a check of your working.
(4)
Answer:
No, only 72 bikes can fit
Step-by-step explanation:
18 x 4.8 is 86.4
2 x .6 is 1.2
86.4 divided by 1.2 is 72
there for only 72 bikes can fit
What is the y-intercept for 6x - 2y = 15
Answer:
-2y=-6x+15
2y=6x-15
y=3x-7.5
y intercept is 7.5
Step-by-step explanation:
make y the subject
ANSWER ASAP PLZZZZZ
NEED HELP WITH THIS QUESTION
Answer:
x=-3
Step-by-step explanation:
whitch lines are perpendicular??
Answer:
A
Step-by-step explanation:
multiple lines meeting at 90 degrees. hope this helped
Someone please help with this!
Answer:
27/1
Step-by-step explanation:
3³=3·3·3=27
27=27/1
the width of a rectangle is 2 m less than the length. if the area of the rectangle is 48sq meters. what is the length and width
HELP ME ON THIS PLEASEEEE!!!
The sum of Jahiem and his sister's age is 21. If Jahiem is 7 years older than his
sister, write and solve a system of equations using ) to represent Jahiem's age and s
to represent his sister's age
Step-by-step explanation:
ANSWER He is 14 and she is 7 because 21 - 7 is 14
What are the zeros of the function g(x) = (x + 6) (x – 4)(x + 2) ?
9514 1404 393
Answer:
x in {-6, -2, 4}
Step-by-step explanation:
The zero product rule tells you that a product will be zero if and only if one of the factors is zero. These binomial factors are zero when x has a value that is opposite the constant of the binomial.
x +6 = 0 ⇒ x = -6
x -4 = 0 ⇒ x = 4
x +2 = 0 ⇒ x = -2
The zeros of the function are the x-values -6, -2, and 4.
Researchers at the National Cancer Institute released the results of a study that investigated the effect of weed-killing herbicides on house pets. The randomly sampled 400 dogs from homes where an herbicide was used on a regular basis, diagnosing lymphoma in 230 of them. Of 200 dogs randomly sampled from homes where no herbicides were used, only 25 were found to have lymphoma. For this problem, let p1 be the population proportion of dogs that get lymphoma from homes where herbicides are used and p2 be the population proportion of dogs that get lymphoma from homes where herbicides are not used. Researchers are interested in learning about the difference in the proportion of cancer diagnoses between the two groups. What is the 95% confidence interval for the difference in the proportion of cancer diagnoses between the two groups
Answer:
The 95% confidence interval for the difference in the proportion of cancer diagnoses between the two groups is (0.3834, 0.5166).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction between normal variables.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
The randomly sampled 400 dogs from homes where an herbicide was used on a regular basis, diagnosing lymphoma in 230 of them.
This means that:
[tex]p_h = \frac{230}{400} = 0.575, s_h = \sqrt{\frac{0.575*0.425}{400}} = 0.0247[/tex]
Of 200 dogs randomly sampled from homes where no herbicides were used, only 25 were found to have lymphoma.
This means that:
[tex]p_n = \frac{25}{200} = 0.125, s_n = \sqrt{\frac{0.125*0.875}{200}} = 0.0234[/tex]
Distribution of the difference:
[tex]p = p_h - p_n = 0.575 - 0.125 = 0.45[/tex]
[tex]s = \sqrt{s_h^2+s_n^2} = \sqrt{0.0247^2 + 0.0234^2} = 0.034[/tex]
Confidence interval:
The confidence interval is:
[tex]p \pm zs[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower bound is [tex]0.45 - 1.96(0.034) = 0.3834[/tex]
The upper bound is [tex]0.45 + 1.96(0.034) = 0.5166[/tex]
The 95% confidence interval for the difference in the proportion of cancer diagnoses between the two groups is (0.3834, 0.5166).
What is the probability that (enter the probability only, do not round.):
• Exactly 2 are male?
• At least 7 are male?
• None are male?
• Less than 3 are male?
• There are 3 or 4 males?
• At least 1 is male?
Answer:
7
Step-by-step explanation:
The required probabilities are
• Exactly 2 are male = 0.08
• At least 7 are male = 0.14
• None are male = 0.60
• Less than 3 are male = 0.12
• There are 3 or 4 males = 0.019
• At least 1 is male = 0.04
Probabilities to college reported that 40% of its population is male. Nine students are selected at random.
Probability can be defined as the ratio of favorable outcomes to the total number of events.
For Exactly 2 are male = 2 * 0.04
= 0.08
Similarly,
• At least 7 are male = 0.14
• None are male = 1 -0.40 = 0.60
• Less than 3 are male = 0.12
• There are 3 or 4 males = 0.12 *0.16 = 0.019
• At least 1 is male = 0.04
Thus, the required probability is given above.
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I am lost and need help asap!
Answer:
<CED = 58°
Step-by-step explanation:
Let <CED = x
We can obtain the value of x as illustrated below:
<CED + 122 = 180 (angles on a straight line)
x + 122 = 180
Collect like terms
x = 180 – 122
x = 58°
<CED = x
x = 58°
Thus,
<CED = 58°
If g(x) = 4x - 9. solve g[g(x)] = g(x) for x.
Answer:
f ( x + 4 /9 ) = 4 x − 65/ 9
Step-by-step explanation:
Question #2
What is the value of the expression
35
?
23 – 1
A 5
B 7
C 12
Answer:
A. 5
Step-by-step explanation:
just use calculator tbh
I need help with #3 and #1
Answer:
1) v = (30 cm)/(0.03 s) = 1000 cm/s = 10m/s
3) The driver is lying. The witness said that the accident happened in a blink of an eye and if the driver was really going at 10 km/hr, he would have only traveled 0.83 m out of the parking lot
Construct and interpret a 95% confidence interval to estimate the proportion of the earth that is water. Show all work. Make sure to check your conditions and state your conclusion.
1.) Randomly selected
2.) Less than 10% of population
3.) 50 (0.68)
50 (0.32)
the answer would be 2
how much will a person pay for 1.5 pounds of bananas at a price of .95 per pound
Answer:
1.425
Step-by-step explanation:
when 1pound is 0.95
then 1.5should be multiplied by 0.95
I need help understanding area with combined shapes
Answer:
Step-by-step explanation:
You can start by splitting one whole complex shape into multiple shapes. Then find the areas of the shapes and add them together. Check the image I attached.
PLEASE HELP!
a-b+c=3
a+b+c=7
Find b.
A) 1
B) 2
C) 3
D) 4
E) 5
Answer:
b
Step-by-step explanation:
I think the day of my birthday was a little more aware of my own life than the poem I think I c I
Answer:
B
Step-by-step explanation:
Given the 2 equations
a - b + c = 3 → (1)
a + b + c = 7 → (2)
Subtract (1) from (2) term by term to eliminate a and c
a - a + b - (- b) + c - c = 7 - 3 , that is
0 + b + b + 0 = 4
2b = 4 ( divide both sides by 2 )
b = 2 → B
How do you rewrite p(x)=-5x2+120x-315 in vertex form
Answer:
[tex]p(x)=-5(x-12)^2+405[/tex]
Step-by-step explanation:
Hi there!
Vertex form: [tex]f(x)=a(x-h)^2+k[/tex]
[tex]p(x)=-5x^2+120x-315[/tex]
Factor out -5 from the first two terms
[tex]p(x)=-5(x^2-24x)-315[/tex]
Complete the square by adding [tex](\frac{24}{2} )^2[/tex] (the square of half of the x-coefficient)
[tex]p(x)=-5(x^2-24x+(\frac{24}{2} )^2)-315-(-5)(\frac{24}{2} )^2[/tex]
We're subtracting [tex](-5)(\frac{24}{2} )^2[/tex] because we need to keep the equation balanced and we can't just add new values.
Complete the square
[tex]p(x)=-5(x-(\frac{24}{2} ))^2-315-(-5)(\frac{24}{2} )^2[/tex]
Simplify
[tex]p(x)=-5(x-12)^2-315+720\\p(x)=-5(x-12)^2+405[/tex]
Summary:
Complete the squareSimplifyI hope this helps!
The scatter plot shows the ages of drivers who attended a car show and the ages of their cars.
What is the age range of drivers who own an 8-year-old car?
The required range of drivers who own 8 years car is 23years.
Given that,
The scatter plot shows the ages of drivers who attended a car show and the ages of their cars.
We have to determine,
The age range of drivers who own an 8-year-old car.
According to the question,
The Range is the difference between the lowest and highest values.
Therefore,
The age range of drivers who own 8 years old car is 17,25 and 40 years.
Then,
Range of drivers who own 8 years car = highest value of range - lowest value of age.
Range of age of drivers who own 8 years car = 40 - 17 = 23years
Hence, The required range of drivers who own 8 years car is 23years.
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Examine the rotation. Which best describes point D?
HELP APA!! I will mark Brainlist THANK YOU!
Answer/Step-by-step explanation:
According to the Hing e Theorem states when two triangles have two congruent sides but have different included angle measure, the largest angle is said to be definitely opposite the longer of the sides.
In the figure given, since both triangles have two corresponding sides that are congruent (BA = BB and BD = BD), and the included angle measure are different, therefore, the greater third side would be the side opposite to the included angle that is the greatest.
Thus, CD is opposite to the greater included angle (28°), therefore, CD> AD