A Test Is Made Of $H _ { 0 } : \mu = 68$

A test is made of $H _ { 0 } : \mu = 68$ versus $H _ { 1 } : \mu \neq 68$ . A sample of size n=60 is drawn, and $\bar { x } = 73 .$ The population standard deviation is $\sigma = 23$ . Compute the value of the test statistic z and determine if $H _ { 0 }$ is rejected at the $a = 0.05$ level.

A) 0.22, $H _ { 0 }$ not rejected
B) 1.68, $H _ { 0 }$ rejected
C) 0.22, $H _ { 0 }$ rejected
D) 1.68, $H _ { 0 }$ not rejected