Question: According to an article on www.PCMag.com, Facebook users spend an average of 190 minutes per month checking and updating their Facebook pages. Suppose that the current distribution of times spent per month checking and updating their Facebook pages by all users is normally distributed with a mean of 190 minutes and a standard deviation of 55.2 minutes. A random sample of 16 Facebook users is selected.

a) Calculate the mean and standard deviation of the sampling distribution of the average amount of time spent per month checking and updating Facebook pages for a random sample of 16 users.

b) Sketch the curve of the sampling distribution, marking the locations and the values of the sample mean time that fall at 1, 2, and 3 standard deviations away from the mean. Shade the region corresponding to the probability of having a sample average of less than 176 minutes per month and calculate this probability

c) Suppose that the distribution mentioned at the beginning of the problem was heavily skewed as opposed to being normal. Would the results in part b be valid? Why/why not?