The file S02_50.xlsx contains the average price of gasoline in each of the 50 states.
a. Compare the distributions of gasoline price data (one for each year) across states. Specifically, do you find the mean and standard deviation of these distributions to be changing over time? If so, how do you explain the trends?
b. In which regions of the country have gasoline prices changed the most?
c. In which regions of the country have gasoline prices remained relatively stable?