​ In a study of government financial aid for college​ students, it becomes necessary to estimate the percentage of​ full-time college students who earn a​ bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.05 margin of error and use a confidence level of 95​%. Complete parts​ (a) through​ (c) below.

a. Assume that nothing is known about the percentage to be estimated.

___ ​(Round up to the nearest​ integer.)

b. Assume prior studies have shown that about 60​% of​ full-time students earn​ bachelor's degrees in four years or less.

___ (Round up to the nearest​ integer.)

c. Does the added knowledge in part​ (b) have much of an effect on the sample​ size?

A. No, using the additional survey information from part​ (b) only slightly reduces the sample size.

B. No, using the additional survey information from part​ (b) does not change the sample size.

C. Yes, using the additional survey information from part​ (b) only slightly increases the sample size.

D. Yes, using the additional survey information from part​ (b) dramatically reduces the sample size.

QUESTION 1  The number of customers per shop per day for a franchised business with nearly 10,000 stores nationwide is 900 people To increase the number of customers, the franchise owner is considering cutting down on the price of coffee drinks To test this new initiative, the store has reduce coffee prices in a sample of 25 stores. It is found that the mean of the number of customers per store in one day is 974 and the standard deviation is 96. At the 0.01 level, indicate whether there is significant evidence that reducing coffee prices is a good strategy to increase the mean of customers

  A study by the Pew Internet and American Life Project found that Americans have a complex and divisive attitude toward technology. This study reports that 8% of respondents are 'Omnivores,' who like gadgets, send text, make videos and upload material to YouTube. Andy believes that the percentage of students at his university 'Omnivores is greater than 8%. Andy took a sample of 200 students at his university and found that 30 students could be classified as' Omnivores. At the 0.05 level, indicate whether there is significant evidence that the percentage of Omnivores in the university is greater than 8%.

A college entrance test company determined that a score of

21

on the mathematics portion of the test suggests that a student is ready for​ college-level mathematics. To achieve this​ goal, the company recommends that students take a core curriculum of math courses in high school. Suppose a random sample of

150

students who completed this core set of courses results in a mean math score of

21.4

on the college entrance test with a standard deviation of

3.4

Do these results suggest that students who complete the core curriculum are ready for​ college-level mathematics? That​ is, are they scoring above

21

on the math portion of the​ test? Complete parts​ a) through​ d) below.

a) State the appropriate null and alternative hypotheses.

​b) Verify that the requirements to perform the test using the​ t-distribution are satisfied. Check all that apply.

​c) Use the​ P-value approach at the

alphaαequals=0.05

level of significance to test the hypotheses in part​ (a).

Identify the test statistic.

Identify the​ P-value.

​d) Write a conclusion based on the results. Choose the correct answer below.

▼

Reject

Do not reject

the null hypothesis and claim that there

▼

is not

is

sufficient evidence to conclude that the population mean is

▼

less

greater

than

21.

1. A small college went online in the middle of the semester in order avoid a virus contagion. They implemented a new online program to help increase students’ access to learning material and continue their classes. The data below is the average number of students that came to class before and after the move to online. The following is the number of students in the class before going online and after going online. The administration clams that there is no relationship between going online and the class attendance and you do not believe this. You are going to use a .10 alpha to conduct a test.

1. What is the Null and Alternative hypotheses? Write them both out below: (2)
2. What is the Critical value of the distribution? Why? (1)
3. Calculate the average difference, standard deviation for the data above: (2)
4. What is the sample statistic above? Show work (2)
5. Do we reject the null hypotheses? Is there evidence that the new system lowers the number of spoiled foods a company has? (3)

1. A community psychologist selects a sample of 16 local police officers to test whether their physical endurance is better than the median score of 72. She measures their physical endurance on a 100-point physical endurance rating scale.

Based on the data given above, compute the one-sample sign test at a 0.05 level of significance.
x =

2. A professor has a teaching assistant record the amount of time (in minutes) that a sample of 16 students engaged in an active discussion. The assistant observed 8 students in a class who used a slide show presentation and 8 students in a class who did not use a slide show presentation.

Use the normal approximation for the Mann-Whitney U test to analyze the data above. (Round your answer to two decimal places.)
z =

In an​ experiment, college students were given either four quarters or a​ $1 bill and they could either keep the money or spend it on gum. The results are summarized in the table. Complete parts​ (a) through​ (c) below.

a. Find the probability of randomly selecting a student who spent the​ money, given that the student was given four quarters.

The probability is

​(Round to three decimal places as​ needed.)

b. Find the probability of randomly selecting a student who kept the​ money, given that the student was given four quarters.

The probability is

​(Round to three decimal places as​ needed.)

c. What do the preceding results​ suggest?

A.

A student given four quarters is more likely to have kept the money than a student given a​ $1 bill.

B.

A student given four quarters is more likely to have kept the money.

C.

A student given four quarters is more likely to have spent the money than a student given a​ $1 bill.

D.

A student given four quarters is more likely to have spent the money.

In a study of government financial aid for college​ students, it becomes necessary to estimate the percentage of​ full-time college students who earn a​ bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.04 margin of error and use a confidence level of 90​%. Complete parts​ (a) through​ (c) below.

a. Assume that nothing is known about the percentage to be estimated.

n=________(Round up to the nearest​ integer.)

b. Assume prior studies have shown that about 60​% of​ full-time students earn​ bachelor's degrees in four years or less.

c. Does the added knowledge in part​ (b) have much of an effect on the sample​ size?

A.

​No, using the additional survey information from part​ (b) does not change the sample size.

B.

​Yes, using the additional survey information from part​ (b) only slightly increases the sample size.

C.

​No, using the additional survey information from part​ (b) only slightly reduces the sample size.

D.

​Yes, using the additional survey information from part​ (b) dramatically reduces the sample size.

a) A manager at the Kemboja Car Sales and Services Enterprise wishes to estimate the number of days it takes for his car dealer to sell a local made car model. A random sample of 50 cars was selected and the mean number of days his car dealer is able to sell a local made car is 50 days. Assume the population standard deviation is 6 days.

i) Find the best point estimate of the population mean. Find the standard error of the

mean.

ii) Calculate the 99% confidence interval of the population mean number of days a car

dealer is able to sell a local made car.

b) As an aid for improving students’ study habit, 6 students were randomly selected to attend a seminar on the importance of education in life. The table shows the number of hours each student studied per week before and after the seminar. At the 95% confidence interval, did attending seminar increase the mean number of hours the students studied per week?

Before 12 15 18 10 13 5 After 17 20 21 15 22 7

Given Σd = - 29; Σd2 = 169

The number of students taking the SAT has risen to an all-time high of more than 1.5 million The number of times the SAT was taken and the number of students are as follows.

a. Let x be a random variable indicating the number of times a student takes the SAT. Show the probability distribution for this random variable. Round your answers to four decimal places.

b. What is the probability that a student takes the SAT more than one time? Round your answer to four decimal places.

c. What is the probability that a student takes the SAT three or more times? Round your answer to four decimal places.

d. What is the expected value of the number of times the SAT is taken? Round your interim calculations and final answer to four decimal places.

e. What is the variance and standard deviation for the number of times the SAT is taken? Round your interim calculations and final answer to four decimal places.

Franklin Training Services (FTS) provides instruction on the use of computer software for the employees of its corporate clients. It offers courses in the clients’ offices on the clients’ equipment. The only major expense FTS incurs is instructor salaries; it pays instructors $6,000 per course taught. FTS recently agreed to offer a course of instruction to the employees of Novak Incorporated at a price of $700 per student. Novak estimated that 20 students would attend the course.

Base your answers on the preceding information.

FTS sells a workbook with printed material unique to each course to each student who attends the course. Any workbooks that are not sold must be destroyed. Prior to the first class, FTS printed 20 copies of the books based on the client’s estimate of the number of people who would attend the course. Each workbook costs $30 and is sold to course participants for $50. This cost includes a royalty fee paid to the author and the cost of duplication.

Calculate the workbook cost in total and per student, assuming that 18, 20, or 22 students attempt to attend the course.

Classify the cost of workbooks as fixed or variable relative to the number of students attending the course.