Hello Kevin! I am sorry that I don't have time to answer all three of these questions in great detail, but I can walk you through the differences between A, B, and C. Part A is what I'd call a basic density curve problem. Calculate a z-score for the lower boundary (46) and the upper boundary (56). Once you get the z-scores, you'd find the area between those two z-scores. Part B and C are similar, but they're referencing Sampling Distributions, which would affect the standard deviation of the statistic that is used for your z-score. For parts B and C, calculate a z-score while remembering that the standard deviation of your statistic is population standard deviation divided by square root of n. For B: standard deviation of statistics is 4 and for C: standard deviation of statistic is 2. I hope this aids you with your calculations. Have a good one now!
