Question 4 (8 marks)

For each of the following standardized test statistics, draw a diagram for a standard normal distribution, shade the area for the p-value, and find the p-value based on a standard normal distribution.

a) ? = 0.85 for a right-tailed test for a mean

b) ? = ?2.19 for a left-tailed test for a difference in two means

c) ? = 1.21 for a left-tailed test for a difference in two means

d) ? = ?12.05 for a two-tailed test for a mean

Question 5 (16 marks)

Many people have high anxiety about visiting the dentist. Researchers want to know if this affects blood pressure in such a way that the mean blood pressure while waiting to see the dentist is higher than it is an hour after the visit. Ten individuals have their systolic blood pressures measured while they are in the dentist's waiting room and again an hour after the conclusion of the visit to the dentist. The data are as follows:

Person 1 2 3 4 5 6 7 8 9 10 Before: 132 135 149 133 119 121 128 132 119 110 After: 118 137 140 130 107 116 122 124 115 103