4. Let X and Y equal, respectively, the blood volumes in milliliters for a paraplegic male participating in vigorous physical activities and for an able-bodied male participating in everyday ordinary activities. Assume that both X and Y are normally distributed. Following are observations for 7 paraplegic males participating in vigorous physical activities: 1612 1352 1456 1222 1560 1456 1924 [ continued on next page] Following are observations for 10 able-bodied males participating in everyday activities: 1082 1300 1092 1040 910 1248 1092 1040 1092 1288 a) Is the standard deviation of blood volumes for able-bodied males significantly different from 150? Create the appropriate 95% confidence interval to answer this question. Explain. b) Can the variances for these two groups of males be assumed equal? Create the appropriate 95% confidence interval to answer this question. Explain