According to a social media? blog, time spent on a certainsocial networking website has a mean of 22 minutes per visit.Assume that time spent on the social networking site per visit isnormally distributed and that the standard deviation is 7 minutes.Complete parts? (a) through? (d) below.

a. If you select a random sample of 25?sessions, what is the probability that the sample mean is between21.5 and 22.5 ?minutes? ___ ?(Round to three decimal places as?needed.)

b. If you select a random sample of 25sessions, what is the probability that the sample mean is between21 and 22 minutes? ___ ?(Round to three decimal places as?needed.)

c. If you select a random sample of 144?sessions, what is the probability that the sample mean is between15.5 and 16.5 ?minutes? ?____ (Round to three decimal places as?needed.)

d. Explain the difference in the results of?(a) and? (c).

The sample size in? (c) is greater than the sample size in? (a),so the standard error of the mean? (or the standard deviation ofthe sampling? distribution) in? (c) is

______ than in? (a). As the standard error _______ values becomemore concentrated around the mean.? Therefore, the probability thatthe sample mean will fall in a region that includes the populationmean will always ______ when the sample size increases.