Inference
1. Suppose the number of residents within five miles of each of your stores is asymmetrically distributed with a mean of 17 thousand and a standard deviation of 10.2 thousand.
What is the probability that the average number of residents within five miles of each store in a sample of 50 stores will be fewer than 18.1 thousand?
Please specify your answer in decimal terms and round your answer to the nearest hundredth (e.g., enter 12 percent as 0.12).
2. Suppose the number of residents within five miles of each of your stores is asymmetrically distributed with a mean of 10 thousand and a standard deviation of 5.1 thousand.
What is the 95th percentile for the average number of residents within five miles of each store in a sample of 65 stores?

Note that the correct answer will be evaluated based on the z-values in the summary table in the Teaching Materials section.

Please specify your answer in thousands and round to the nearest tenth (e.g., enter 6,531 as 6.5).
3. Suppose the shipping weight of your cheese shop’s customized gift baskets is asymmetrically distributed with unknown mean and standard deviation. For a sample of 65 orders, the mean weight is 45 ounces and the standard deviation is 10.2 ounces.
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What is the upper bound of the 90 percent confidence interval for the gift basket’s average shipping weight?

Note that the correct answer will be evaluated based on the z-values in the summary table in the Teaching Materials section.
Please round your answer to the nearest tenth.

Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.
4. Suppose the average commute time of your employees is unknown. The standard deviation of their commute time is estimated as 35.1 minutes.

How many employees must be included in a sample to create a 95 percent confidence interval for the average commute time with a confidence interval width of no more than 18 minutes?

Note that the correct answer will be evaluated based on the z-values in the summary table in the Teaching Materials section.

Remember to round your answer up to an integer.

Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.
5. Suppose you are working for a regional residential natural gas utility. For a sample of 85 customer visits, the staff time per reported gas leak has a mean of 228 minutes and standard deviation 36 minutes. The VP of network maintenance hypothesizes that the average staff time devoted to reported gas leaks is 237 minutes.

At a 1 percent level of significance, what is the lower bound of the interval for determining whether to accept or reject the VP’s hypothesis?

Note that the correct answer will be evaluated based on the z-values in the summary table in the Teaching Materials section.
Please round your answer to the nearest tenth.

Note that the correct answer will be evaluated based on the full-precision result you would obtain using Excel.

Excel Basics
1. In a spreadsheet create a function that generates for any value x the corresponding value y when y = 12x + 15. What is the value y when x = 10? Please specify your answer as an integer.

2. In a spreadsheet create a function that generates for any value x the corresponding value y when y = 10×2 + 7x – 1. What is the value y when x = 8? Please specify your answer as an integer.

3. In a spreadsheet create a function that generates for any value x the corresponding value y when y = (4/7)x2 – 6x + 10. What is the value y when x = 11? Please round your answer to the nearest hundredth.

4. In a spreadsheet create a function that generates for any value x the corresponding value y when y = (10/7)(1/x) – 15. What is the value y when x = 14? Please round your answer to the nearest thousandth.

5. Consider the following set of numbers: 18, 15, 20, 11, and 14. Using a spreadsheet for computations, what is the sum of the numbers? Please specify your answer as an integer.

6. Consider the following set of numbers: 19, 14, 13, 17, and 12. Using a spreadsheet for computations, what is the product of the numbers? Please specify your answer as an integer.

7. Consider the following set of numbers: 12, 15, 11, 16, and 20. Using a spreadsheet for computations, what is the average of the numbers? Please round your answer to the nearest hundredth.

8. Design a spreadsheet to compute the dollar amount in each of the next 10 years of an initial investment returning a constant annual interest rate. Interest is reinvested each year so that the amount returning interest grows. What is the dollar amount 10 years from now of $500 invested at 6% annual interest? Please round your answer to the nearest hundredth.

9. Suppose revenues for a small business are $60,000 this year and will grow 9% per year. Design a spreadsheet to compute revenue in each of the next 10 years. In how many years from now will revenues first exceed $108,000? Please specify your answer as an integer.

10. Suppose a small business has sales of $14,000 this month, with future sales expected to grow by $1,300 each month. Costs consist of a fixed component, which is $8,400 per month, and a variable component, which is 25 percent of sales. Design a spreadsheet to compute the gross profit (revenue less fixed and variable costs) per month over a nine month period. What is the gross profit in a single month 8 months from now? Please specify your answer as an integer.