A study was conducted to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours.We are 95% confident that the mean number of weekly hours that U.S. adults use computers at home falls between which of the following intervals? 7.3 and 9.7 7.7 and 9.3 8.4 and 8.6 6.5 and 10.5 8.1 and 8.9

A study was conducted to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours. The 95% confidence interval for the mean, μ, is (7.7, 9.3).Which of the following will provide a more informative (i.e., narrower) confidence interval than the 95% confidence interval? Check all that apply. Using a sample of size 400 (instead of 81) Using a sample of size 36 (instead of 81) Using a different sample of size 81 Using a 90% level of confidence (instead of 95%) Using a 99% level of confidence (instead of 95%)

A study was conducted to estimate μ, the mean commute distance that all employed U.S. adults travel to work. Suppose a random sample of 49 employed U.S. adults gives a mean commute distance of 22 miles and that from prior studies, the population standard deviation is assumed to be σ = 8.4 miles.We are 95% confident that the mean commute distance to work of all employed U.S. adults falls between which of the following intervals? 5.2 to 38.8 19.6 to 24.4 20.8 to 23.2 18.4 to 25.6

A simple random sample of seven (7) students is selected, and the students are asked how much time they spent studying for their University subjects (combined) outside class times. From past experience, it is known that these times (in hours) are distributed normally.The times (in hours) for the sample of students are as follows:2.3 7.2 4.5 12.5 6.6 2.5 5.5Based on these results, a confidence interval estimate for the population mean is found to be 5.9 ± 2.6.The level of confidence the researcher has used is closest to:-Group of answer choices95%90%97.5%99%

Here are the number of hours that 9 students spend on the computer on a typical day:1 6 7 6 8 11 6 12 15Which of the following represents the mean number of hours spent on the computer? 6.0 7.0 8.0 9.0

A study conducted by a technology company showed that the mean time spent per day browsing the video streaming service Netflix for something to watch was 20.6 minutes. Assume the standard deviation is =σ8. Suppose a simple random sample of 102 visits taken this year has a sample mean of =x19.6 minutes. A social scientist is interested to know whether the mean time browsing Netflix has decreased. Use the =α0.05 level of significance and the P-value method with the TI-84 Plus calculator.Part: 0 / 50 of 5 Parts CompletePart 1 of 5(a) State the appropriate null and alternate hypotheses.H0: 20.6H1: 20.6