Suppose that the average time spent per day with digital media several years ago was 3 hours and 33 minutes. For last year, a random sample of 20 adults in a certain region spent the numbers of hours per day with digital media given in the accompanying table. Preliminary data analyses indicate that the t-interval procedure can reasonably be applied. Find and interpret a 95% confidence interval for last year's mean time spent per day with digital media by adults of the region. (Note: x? = 5.02 hr and s = 2.22 hr.) Click here to view the digital media times. Click here to view page 1 of the t-table. Click here to view page 2 of the t-table. The 95% confidence interval is from ? ? hour(s) to ? ? hour(s). (Round to two decimal places as needed.) Interpret the 95% confidence interval. Select all that apply. ? A. There is a 95% chance that the mean amount of time spent per day on digital media last year by all adults in the region is between the interval's bounds. ? B. 95% of all possible random samples of 20 adults in the region have mean amounts of time spent per day on digital media last year that are between the interval's bounds. ? C. 95% of all adults in the region spent amounts of time per day on digital media last year that are between the interval's bounds. ? D. With 95% confidence, the mean amount of time spent per day on digital media last year by all adults in the region is between the interval's bounds.
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Given: - Sample mean (\(\bar{x}\)) = 5.02 hours - Sample standard deviation (s) = 2.22 hours - Sample size (n) = 20 - Confidence level = 95% The formula for the confidence interval for the population mean (\(\mu\)) using the t-distribution is: \[ \bar{x} \pm Show more…
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