9.8 A random sample of n = 25 is obtained from a population with variance s2, and the sample mean is computed.

Test the null hypothesis H0 : m = 120 versus the alternative hypothesis H1 : m 7 120 with a = 0.10.

Compute the critical value xc and state your decision rule for the following options.

a. The population variance is s2 = 196.

b. The population variance is s2 = 625.

c. The population variance is s2 = 900.

d. The population variance is s2 = 500.