Chapter 9 - Inferences from Two Samples - 9-5 Two Variances or Standard Deviations - Basic Skills and Concepts - Page 482: 1

a) No. b)No. c) Have to be equal.

a) $s_1^2>s_2^2$ and the F-statistic is:$F=\frac{s_1^2}{s_2^2}$ is more than $\frac{s_2^2}{s_2^2}=1$, hence no. b) $s_1^2$and $s_2^2$ are both postitive, hence $F=\frac{s_1^2}{s_2^2}$ is also positive, hence no. c) The F-statistic is the quotient of the sample variances, hence they have to be equal.