In a 2018 poll conducted by SurveyMonkey, they randomly surveyed 368 students

from two- and four-year institutions across the U.S. According to the survey, 58% purchased at

least one of their textbooks on Amazon. What proportion of all U.S. college students purchased

at least one of their textbooks on Amazon?

a. Use StatCrunch to find a 95% confidence interval: _________________

b. Interpret your confidence interval in words.

c. True or False: A 90% confidence interval would be wider than a 95% confidence interval.

d. If the true proportion of all U.S. college students who purchased at least one of their

textbooks on Amazon was 62%, does our confidence interval support or refute it?

1. Based on past experience, a bank believes that 7% of the people who receive loans will not make payments on time. The bank takes a random sample of 200 recently approved loans.

   1. What values of sample proportions of clients who will not make timely payments would be unusual? Explain.

   2. Construct and interpret a 95% confidence interval for the true proportion of clients who will not make timely payments.

   3. Since the U.S. economy has changed, bank officials would like to do a new study to estimate the true proportion of clients who will not make timely payments. Assume you have no preconceived idea of what that proportion would be. What sample size is needed if you wish to be 99% confident that your estimate is within 2% of the true proportion.   

   4. Based on previous research, you assume the proportion of clients who will not make timely payments is 7%. What sample size is needed if you wish to be 99% confident that your estimate is within 2% of the true proportion.

They have available 10 boxes of honey, 4 boxes of el Duende, 6 boxes of bimbos, 15 boxes of oreos . Each sells for 6$.

a) Define your random variable.

b) Determine the probability distribution and parameters for the random variable.

c)Suppose that, after two hours, ten boxes of them have been purchased. Determine the cumulative distribution function for the number of honey purchased.

d)Draw the probability distribution function for the number of honey purchased.

Some body please hurry

A random sample of 64 observations is to be been drawn from a distribution with mean
15 and standard deviation 10. Find the probability that the sample mean, x̅ , will differ
from μ by no more than 2 units in either direction. Interpret your results.

According to a recent​ report, 46% of college student internships are unpaid. A recent survey of 60 college interns at a local university found that 31 had unpaid internships.

a. Use the​ five-step p-value approach to hypothesis testing and a 0.05 level of significance to determine whether the proportion of college interns that had unpaid internships is different from 0.46.

b. Assume that the study found that 3838 of the 6060 college interns had unpaid internships and repeat​ (a). Are the conclusions the​ same?

The data below represent scores from three different therapies used to treat depressive symptoms. Scores represent depressive symptoms on a scale of 1-10, with higher scores indicating greater depressive symptoms.

a.   SS_T is what?
b.   SS_W is what?
c.   SS_B is what?
d    df_T is what?
e.   df_W is what?
f.   df_B is what?
g.   MS_B is what?
h.   MS_W is what?
i.   F is what?
j.   η² is what?
k.   Statistically significant?
l.   Tukey HSD critical value is what?
m. APA Conclusion?

Two employees are counting the number of broken eggs they find in the large 18 packs of eggs at the store they work at. The first employee records the following numbers of broken eggs in each pack:

0,0,1,1,1,1,1,2,2

(a) What is the median number of broken eggs in a pack?

(b) What is the mean number of broken eggs in a pack?
(c) What is the standard deviation of the number of broken eggs in a pack?

Suppose the second employee reports checking 35 more packs, and found every single pack had 1 broken egg. For the next questions, we will analyze the data of both employees combined (so the above numbers, together with 35 more entries of 1). You don’t need to compute the following statistics, but you need to compare them to the answers from parts a, b, and c with only the first employee’s numbers.

(d) How will the new information from the second employee change the mean? Why?

(e) How will the new information from the second employee change the standard deviation? Why?

A geological research institute tracks temperatures in various locations on the globe. To find out whether average temperatures have changed in the last 25 years, the average temperatures which were recorded for 30 locations in 1994 were compared to the average temperatures which were recorded in 2019 for those same locations. The result: The mean of the 30 temperature differences is 0.207 degrees Celsius, and their SD is 0.68 degrees Celsius.

What type of hypothesis test is appropriate? Justify your answer.

3. The following data are weights of food (in kilograms) consumed per day by adult deer collected at different times of the year.

Month Weight of food consumed (kg)

Feb. 4.7, 4.9, 5.0, 4.8, 4.7

Mar. 4.6, 4.4, 4.3, 4.4, 4.1, 4.2

Oct. 4.8, 4.7, 4.6, 4.4, 4.7, 4.8

Dec. 4.9, 5.2, 5.4, 5.1, 5.6

1. (a) Is there any difference in the food consumption for all the months studied?

2. (b) If food consumption is not the same for all the months, which ones are different (you must show the test used and results for interpretation)?

A consumer product testing organization uses a survey of readers to obtain customer satisfaction ratings for the nation's largest supermarkets. Each survey respondent is asked to rate a specified supermarket based on a variety of factors such as: quality of products, selection, value, checkout efficiency, service, and store layout. An overall satisfaction score summarizes the rating for each respondent with 100 meaning the respondent is completely satisfied in terms of all factors. Suppose sample data representative of independent samples of two supermarkets' customers are shown below.

(a) Formulate the null and alternative hypotheses to test whether there is a difference between the population mean customer satisfaction scores for the two retailers. (Let μ₁ = the population mean satisfaction score for Supermarket 1's customers, and let μ₂ = the population mean satisfaction score for Supermarket 2's customers. Enter != for ≠ as needed.)

H₀:

H_a:

(b) Assume that experience with the satisfaction rating scale indicates that a population standard deviation of 15 is a reasonable assumption for both retailers. Conduct the hypothesis test.

Calculate the test statistic. (Use μ₁ − μ₂. Round your answer to two decimal places.)

test statistic =

Report the p-value. (Round your answer to four decimal places.)

p-value =

At a 0.05 level of significance what is your conclusion?

Reject H₀. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.

Reject H₀. There is not sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.    

Do not reject H₀. There is not sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.

Do not reject H₀. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers.

(c) Which retailer, if either, appears to have the greater customer satisfaction?

Supermarket 1, Supermarket 2, or  neither

Provide a 95% confidence interval for the difference between the population mean customer satisfaction scores for the two retailers. (Use x₁ − x₂. Round your answers to two decimal places.)

The members of a consulting firm rent cars from three rental agencies. It is estimated that 0.39 percent of cars come from agency 1, 0.08 percent of cars come from agency 2, and 0.53 percent of cars come from agency 3. It is also estimated that 0.07 percent of cars from agency 1 need a tune-up, 0.05 percent of cars from agency 2 need a tune-up, and 0.03 percent of cars from agency 3 need a tune-up. Answer the following questions, rounding your answers to two decimal places where appropriate.

(a) What is the probability that a rental car delivered to the firm will need a tune-up?

(b) If a rental car delivered to the firm needs a tune-up, what is the probability that it came from agency 2?

A judging panal of 7people is to be randomly selected from 8 teachers and 20 students.What is the probability that there are more students than teachers on the panal?

A sample of 8 children in the 5th grade of North Stratfield School run the 100 meter dash in a average time of 20.2 seconds. Assume the bias adjusted sample standard deviation of the individual 100 meter dash times is 7.1 seconds.
Construct a 99% confidence interval for μ, the true population mean 100 meter dash time. Since n is small, the t statistic will be used in deriving this confidence interval.
What is the degrees of freedom parameter that should be used to derive the t-value?

The Crown Bottling Company has just installed a new bottling process that will fill 16-ounce bottles of the popular Crown Classic Cola soft drink. Both overfilling and underfilling bottles are undesirable: Underfilling leads to customer complaints and overfilling costs the company considerable money. In order to verify that the filler is set up correctly, the company wishes to see whether the mean bottle fill, μ, is close to the target fill of 16 ounces. To this end, a random sample of 39 filled bottles is selected from the output of a test filler run. If the sample results cast a substantial amount of doubt on the hypothesis that the mean bottle fill is the desired 16 ounces, then the filler’s initial setup will be readjusted.
(a) The bottling company wants to set up a hypothesis test so that the filler will be readjusted if the null hypothesis is rejected. Set up the null and alternative hypotheses for this hypothesis test.

H₀ : μ (Click to select)≠= 16 versus H_a : μ (Click to select)=≠ 16

(b) Suppose that Crown Bottling Company decides to use a level of significance of α = 0.01, and suppose a random sample of 39 bottle fills is obtained from a test run of the filler. For each of the following four sample means— x¯x¯ = 16.05, x¯x¯ = 15.95, x¯x¯ = 16.03, and x¯x¯ = 15.97 — determine whether the filler’s initial setup should be readjusted. In each case, use a critical value, a p-value, and a confidence interval. Assume that σ equals .1. (Round your z to 2 decimal places and p-value to 4 decimal places and CI to 3 decimal places.)

x¯x¯ = 16.05

CI            [, ]   (Click to select)Do not readjustReadjust

x¯x¯⁢ = 15.95

CI              [, ]   (Click to select)Do not readjustReadjust

x¯x¯⁢ = 16.03

CI                  [, ]   (Click to select)Do not readjustReadjust

x¯x¯⁢ = 15.97

CI              [, ] (Click to select)ReadjustDo not readjust

I would like to test a hypothesis that the percentage of people who consider themselves as conservatives today is lower than it was 20 years ago. Conveniently enough, my old professor has data from 20 years ago when he conducted a similar survey. The number of people 20 years ago who identified as conservative in his survey was 314 out of 612 total. I conduct a survey today and find that out of the 415 people i surveyed, 198 considered themselves to be conservative. If i wish to present my findings with a level of significance of .05, what conclusion would i draw?

options:

based on the data, there's evidence of a decrease in those who identify as conservative.

based on the data, there's no evidence of a decrease in those who identify as conservative.

based on the data, there's evidence of an increase in those who identify as conservative.

based on the data, there's no evidence of an increase in those who identify as conservative.