Table P-21 contains the weekly sales for a food item for 52 consecutive weeks. a. Plot the

Question:

Table P-21 contains the weekly sales for a food item for 52 consecutive weeks.

a. Plot the sales data as a time series.
b. Do you think this series is stationary or nonstationary?
c. Using Minitab or a similar program, compute the autocorrelations of the sales series for the first 10 time lags. Is the behavior of the autocorrelations consistent with your choice in part b? Explain.