Separately for each depth, evaluate differences between the sites within and outside

a. Compare the mean drop in blood pressure for the high-dose group and the control

group. Use a ⫽ .05 and report the level of significance.

b. Estimate the size of the difference in the mean drop for the high-dose and control

groups using a 95 confidence interval.

c. Do the conditions required for the statistical techniques used in a and b appear to

be satisfied? Justify your answer. 6.51 Refer to Exercise 6.50. a. Compare the mean drop in blood pressure for the low-dose group and the control group. Use a ⫽ .05 and report the level of significance.

b. Estimate the size of the difference in the mean drop for the low-dose and control

groups using a 95 confidence interval.

c. Do the conditions required for the statistical techniques used in a and b appear to

be satisfied? Justify your answer. 6.52 Refer to Exercise 6.50. a. Compare the mean drop in blood pressure for the low-dose group and the high-dose group. Use a ⫽ .05 and report the level of significance.

b. Estimate the size of the difference in the mean drop for the low-dose and high-dose

groups using a 95 confidence interval.

c. Do the conditions required for the statistical techniques used in a and b appear to

be satisfied? Justify your answer. 6.53 In Exercises 6.50 – 6.52, we tested three sets of hypotheses using portions of the same data sets in each of the sets of hypotheses. Let the experiment-wide Type I error rate be defined as the probability of making at least one Type I error in testing any set of hypotheses using the data from the experiment.

a. If we tested each of the three sets of hypotheses at the .05 level, estimate the experiment-

wide Type I error rate.

b. Suggest a procedure by which we could be ensured that the experiment-wide Type I

error rate would be at most .05. Two-sample T for Low Dose vs Control N Mean StDev SE Mean Low Dose 20 3.8 44.0 9.8 Control 20 29.8 34.0 7.6 95 CI for mu Low Dose mu Control: 51.3, 0.8 T-Test mu Low Dose mu Control vs not : T 2.09 P 0.044 DF 35 -------------------------------------------------------------------------------- Two-sample T for High Dose vs Control N Mean StDev SE Mean High Dose 20 68.4 24.5 5.5 Control 20 29.8 34.0 7.6 95 CI for mu High Dose mu Control: 19.5, 57.6 T-Test mu High Dose mu Control vs not : T 4.12 P 0.0002 DF 34 -------------------------------------------------------------------------------- Two-sample T for Low Dose vs High Dose N Mean StDev SE Mean Low Dose 20 3.8 44.0 9.8 High Dose 20 68.4 24.5 5.5 95 CI for mu Low Dose mu High Dose: 87.6, 41.5 T-Test mu Low Dose mu High Dose vs not : T 5.73 P 0.0000 DF 29