. CoastCo Insurance, Inc., is interested in forecasting annual larceny thefts in the United States using the following data:
a. Prepare a time-series plot of these data. On the basis of this graph, do you think there is a trend in the data? Explain.
b. Look at the autocorrelation structure of larceny thefts for lags of 1, 2, 3, 4, and 5. Do the autocorrelation coefﬁcients fall quickly toward zero? Demonstrate that the critical value for rk is 0.417. Explain what these results tell you about a trend in the data.
c. On the basis of what is found in parts a and b, suggest a forecasting method from Table 2.1 that you think might be appropriate for this series.