11.79 Dentists make many people nervous. To see whether such nervousness elevates blood pressure, the blood pressure and pulse rates of 60 subjects were measured in a dental setting and in a medical setting (“The Effect of the Dental Setting on Blood Pressure Measurement,”

American Journal of Public Health [1983]: 1210– 1214).

For each subject, the difference (dental-setting blood pressure minus medical-setting blood pressure) was calculated. The analogous differences were also calculated for pulse rates. Summary data follow.

Mean Difference Standard Deviation of Differences Systolic Blood Pressure 4.47 8.77 Pulse (beats/min) 21.33 8.84

a. Do the data strongly suggest that true mean blood pressure is greater in a dental setting than in a medical setting? Use a level .01 test.

b. Is there sufficient evidence to indicate that true mean pulse rate in a dental setting differs from the true mean pulse rate in a medical setting? Use a significance level of .05.