Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 90% confident that the population mean is within 7 minutes of the sample mean? Assume the population standard deviation is 36 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least people.

Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 95% confident that the population mean is within 7 minutes of the sample mean? Assume the population standard deviation is 36 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least people. ol

The coefficient of variation CV describes the standard deviation as a percent of the mean. Because it has no units, you can use the coefficient of variation to compare data with different units. Find the coefficient of variation for each sample data set. What can you conclude? Standard deviation CV = • 100% Mean E Click the icon to view the data sets. Data Table ..... CVneights = 71.2% (Round to the nearest tenth as needed.) Heights Weights 68 181 77 169 72 167 72 207 71 177 70 175 78 185 69 186 67 221 70 216 67 209 73 206

← The numbers of regular season wins for 10 football teams in a given season are given below. Determine the range, mean, variance, and standard deviation of the population data set. 2, 10, 15, 4, 12, 9, 13, 10, 5, 7 The range is 13. (Simplify your answer.) The population mean is 8.7. (Simplify your answer. Round to the nearest tenth as needed.) The population variance is 15.6. (Simplify your answer. Round to the nearest tenth as needed.) The population standard deviation is (Simplify your answer. Round to the nearest tenth as needed.)

Find the Mean, Median and Standard Deviation for the data. Round to two decimal places. 10,7,9,3,8,15,5,5,12

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Use the expression in the accompanying discussion of sample size to find the size of each sample if you want to estimate the difference between proportions of men and women who own smartphones. Assume that you want 95​% confidence that your error is no more than 0.03.

You are asked to find some descriptive statistics for the heartrate data. Use the methods in the practice activity as a guide to help you find the mean, median, and standard deviation for the heartrate data. Mean: 74.1 Median: 74 Standard Deviation: 6.5 Which measure of central tendency is the most appropriate for the heartrate data?