The Quick Pass CPA Review Co., charges $10,000 for its review classes, and offers a money-back guarantee, if the student does not pass on the first try. The company collected $500,000 from students in its first class, which was held from July through October of 2019. Since the grades of the students on the November test will not be known until January 2020, the owner of Quick Pass intends to not recognize any income until the number of students who actually passed is known, so that he can report income and refund in the same year. What is your advice to your client?

A university official wishes to determine whether the degree of the instructor is related to the students’ opinion of the quality of instruction received. A sample of students’ evaluations of various instructors is selected, and the data in the table below are obtained. At a = 0.10, can the officials conclude that the degree of the instructor is related to the opinions of the students about the instructor’s effectiveness in the class?

a) Identify the appropriate test. Why do you consider this test to be the most appropriate for analyzing this study?

b) State the hypotheses.

1. Thirty GPAs from a randomly selected sample of statistics students at a college reported a mean of 3.11 and the standard deviation was 0.36. Assume that the population distribution is approximately Normal. The technician in charge of records claimed that the population mean GPA for the whole college is 2.88. The chair of the mathematics department claims that students typically have higher GPAs than the typical college student. Test this claim.
   1. State the null and alternative hypotheses
   2. Find the test statistic t.
   3. Find the p-value.
   4. Do you reject or not reject the null hypothesis?
   5. What can you conclude about the mean GPA for statistic students?

The school has 600 students in years 1–6 with 100 students in each year.

1. Shannon got the names of all 600 students in the school and put them in a hat. Then she pulled out 60 names. What do you think of Shannon’s survey? Explain your answer.
2. Jake asked 10 children at an after-school meeting of the computer games club. What do you think of Jake’s survey? Explain your answer.
3. Adam asked all of the 100 children in year 1. What do you think of Adam’s survey? Explain your answer.

A random group of students was surveyed to determine how many months it has been since they visited the dentist. The sample of 32 students gave a mean average of 19 months with a standard deviation of 4.4 months.

a) Find a 95% confidence interval for the population mean number of months since students have seen the dentist. Write answer in a full sentence.

b) Find a 99% confidence interval for the same value. Write answer in a full sentence.

c) Determine the minimum sample size needed to determine the a 95% confidence interval to within 1 month of the population mean.

A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information. Today (Population 1) Five Years Ago (Population 2) Sample Mean 84 89 Sample Variance 112.5 54 Sample Size 45 36 The 92.50% confidence interval for the difference between the two population means is (Round your answers to 2 decimal places.

Suppose that a principal of a local high school tracks the number of minutes his students spend texting on a given school day. He finds that the distribution of minutes spent texting is roughly normal with a mean of 60 and a standard deviation of 20. Use this information to answer the following questions.

1. Based on the statistics, find the two numbers of minutes that define the middle 95% of students in the distribution. What is the value for the lower number that you found?

2. Based on the statistics, find the two numbers of minutes that define the middle 95% of students in the distribution. What is the value for the higher number that you found?

2020 Election ~ Bernie Sanders is a popular presidential candidate among university students for the 2020 presidential election. Leading into Michigan’s presidential primary election in 2020, a journalist, Lauren took a random sample of 11,663 university students and found that 8,891 of them support Bernie Sanders.

Using this data, Lauren wants to estimate the actual proportion of university students who support Bernie Sanders.

What is the required sample size to calculate a 95% confidence interval within 3.05 percentage points? Use z*=1.96.z*=1.96.

n=p*(1−p*)(z*ME)2