Question: A sample of the various prices for a particular product has been conducted in 16 stores which were selected at random in a neighbourhood of a city. The following prices were noted:
95, 108, 97, 112, 99, 106, 105, 100, 99, 98, 104, 110, 107, 111, 103, 110.
Assuming that the prices of this product follow a normal law of variance of 25 and an unknown mean:
a. What is the distribution of the sample mean?
b. Determine the confidence interval at 95% for the population mean.