State the null hypothesis, Ho, and the alternative hypothesis, Ha, that would be used to test the following claims:
a. The standard deviation of population X is smaller than the standard deviation of population Y.
b. The ratio of the variances of population A over population B is greater than 1.
c. The standard deviation of population Q1 is at most that of population Q2.
d. The variability within population I is more than the variability within population II.