Exhibit 20

Exhibit 20.13.An energy analyst wants to test if U.S.oil production is random over time.The analyst has monthly production values for the two years.The analyst finds 12 months are above the median,12 months are below the median,6 runs are below the median,and 5 runs are above the median. Refer to Exhibit 20.13.To test the random-walk hypothesis about oil production,the competing hypothesis are:

A)
B)
C)
D)