Exhibit 20

Multiple Choice

Exhibit 20.7.A marketing firm needs to replace its existing network provider,and is considering three different providers.A primary consideration is the amount of system down time.The following table contains the amount of network down-time (in hours) for the last five months for each network provider. Refer to Exhibit 20.7.At the 5% significance level,the critical value is

A) 4.605
B) 5.991
C) 7.378
D) 9.21