Questions 2-5 below all pertain to the following scenario:

A study is performed to estimate the mean change in serum cholesterol among patients given who start onstatins. Letchangestand for the parameter of scientific interest. To estimatechangewe plan to collect data from 16 patients. Let X1, X2, ...X16 be the changes in cholesterol experienced by these patients and stand for the average of these values that we will calculate.

Isa random variable?