1 Sales volume last weekend for a sample of ten car dealerships were as follows:
Data Point 1 2 3 4 5 6 7 8 9 10
# Sales 44 12 20 49 23 30 34 21 14 36
What is the mean of the sample data?
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.
2 Sales volume last weekend for a sample of ten car dealerships were as follows:
Data Point 1 2 3 4 5 6 7 8 9 10
# Sales 23 13 37 46 20 15 26 45 33 38
What is the standard deviation of the sample data?
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.
3 Sales volume last weekend for four samples, each consisting of five car dealerships, were as follows:
Data Point 1 2 3 4 5
Sample 1 33 24 19 45 30
Sample 2 41 32 19 22 43
Sample 3 45 13 21 33 36
Sample 4 17 20 46 31 28
What is the mean of the distribution of sample means?
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 Sales volume last weekend for four samples, each consisting of five car dealerships, were as follows:
Data Point 1 2 3 4 5
Sample 1 33 24 19 45 30
Sample 2 41 32 19 22 43
Sample 3 45 13 21 33 36
Sample 4 17 20 46 31 28
What is the variance of the distribution of sample means?
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.
5 The mean is 43.6 and the standard deviation is 18.2 for a population.
Using the Central Limit Theorem, what is the standard deviation of the distribution of sample means for samples of size 50?
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.
6 Suppose your marketing colleague used a known population mean and standard deviation to compute the standard error as 56.8 for samples of a particular size. You don't know the particular sample size but your colleague told you that the sample size is greater than 60. Your boss asks what the standard error would be if you triple the sample size.
What is the standard error for the new sample size?
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.
1 Suppose the number of residents within five miles of each of your stores is asymmetrically distributed with a mean of 18 thousand and a standard deviation of 11.7 thousand.
What is the probability that the average number of residents within five miles of each store in a sample of 60 stores will be more than 20.4 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 15 thousand and a standard deviation of 4.9 thousand.
What is the 95th percentile for the average number of residents within five miles of each store in a sample of 70 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 60 orders, the mean weight is 68 ounces and the standard deviation is 11.4 ounces.
What is the lower bound of the 95 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 make 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 95 customer visits, the staff time per reported gas leak has a mean of 219 minutes and standard deviation 34 minutes. The VP of network maintenance hypothesizes that the average staff time devoted to reported gas leaks is 226 minutes.
At a 5 percent level of significance, what is the upper 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.