Return to the discussion of other forms of autocorrelation in section 9.9.

(a) Why might the frequency of traffic accidents on different days display seventh-order autocorrelation?

(b) Why might end-of-day stock market indices display fifth-order autocorrelation?

(c) Why might 12th-order autocorrelation occur in monthly data?

(d) Explain how first-, second-, third-, tenth-, eleventh-, twelfth-, thirteenth-, and fourteenth-order autocorrelation might all appear in the same series of monthly data.