1.3. (10%) A state highway patrol periodically samples vehicle speeds at various locations on a particular highway system into order to test vehicle speeds $H_o: \mu \leq 65$ vs $H_a: \mu > 65$. A sample of 36 vehicles will be selected and the population standard deviation is assumed to be 12 miles per hour. At 0.05 level of significance, what is the probability of making a Type II error when the actual mean speed is 66 miles per hour? ($Z_{0.05} = 1.645$)