Term: August 30, 2017 to October 4, 2017

Direction: Do all of the assigned problems. On day of the quiz, a subset of these problems will be given in class for the quiz. If you are absent from the quiz, the makeup quiz will not be solely based on this review sheet but anything covered from weeks 1, 2 and 3. Please note: this is an individual effort meaning that no outside collaborations are allowed. If collaborations do occur, a grade of zero will be assigned to all parties involved.

1. The Medicare program maintains a sample of 5% of its participants. When a person is selected into the sample, they are followed until their death, and Medicare tracks the services they use and the associated costs. When someone dies, or when the number of enrollees increases (as has happened each year since the program began, due to the Baby Boomers), additional people are enrolled, and these are chosen at random from all current Medicare patients not currently in the sample. In what way is the sample not representative of the population of Medicare patients?Explain.

2. You want to place a confidence interval (CI) on the correlation between grades and income. For 100 people, you find that the sample correlation is 0.4 You resample 20 times from that sample (with replacement) and find the following correlations: 0.2, 0.3, 0.4, 0.5 0.25, 0.35, 0.45, 0.55, 0.23, 0.33, 0.43, 0.53, 0.21, 0.32, 0.42, 0.52, 0.24, 0.34, 0.44, 0.54 0.25 or 0.26. Find a 95% confidence interval. Does this confidence interval make sense? Explain (just giving a yes or no is not an explanation, so no points will be given).

3. On average, class is interrupted by 2.3 phone tones each lecture. Assume each class period is 60 minutes.

i. What type of probability distribution does this represent? Explain why? No explanation means no points.

ii. Given this distribution, what is the expected value? Standard deviation?

4. You manufacture 50 chips. Each chip has probability of failing equal to 1/5 and you want to know if 12 or more fail.

a. What type of distribution would this represent? Why?

b. What is the value of 12 called?

c. What is the expected value, variance, and standard deviation for this manufacture of chips?

5. What is the central limit theorem and why is it important in inferential statistics? (Note: Copying the definition from the notes and/or textbooks is not explanation)

6. A sample of 10 University of Phoenix students have sample mean GPA 3.00 and sample standard deviation 0.4. Create a 99% confidence interval on the mean GPA of all University of Phoenix students. Suppose at random a GPA of a student is 2.10. Does this parameter fall within this interval? Would you have confidence in this GPA of 2.10?

7. List all, and only, the true statements.

A. Holding all else constant, as confidence increases, the width of the interval decreases. B. Holding all else constant, as σ increases, the width of the interval decreases.

C. Holding all else constant, as n increases, the width of the interval decreases.

D. Holding all else constant, as the FPCF increases, the width of the interval decreases.

8. The Nielsen Company compiled a list of the top 25 advertisers in African American media. Shown below are a Minitab descriptive statistics analysis of the annual advertising spending in $ million by these companies in African American media and a box plot of these data. Study this output and summarize the expenditures of these top 25 advertisers in your own words. SE Mean is just the standard error and StDev is the standard deviation, Q1 and Q3 are first and third quartiles.

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