A blood pressure measurement consists of two numbers: the systolic pressure, which is the maximum pressure taken when the heart is contracting; and the diastolic pressure, which is the minimum pressure taken at the beginning of the heartbeat. Blood pressures were measured in millimeters of mercury (mmHg) for a sample of eight adults. The following table presents the results.
Systolic Diastolic
127 92
125 94
135 87
110 75
123 89
121 87
118 87
127 93
The least-squares regression equation is y = 18.7841 + 0.5616x. If the systolic pressures of two patients differ by 8 mmHg, by how much would you predict their diastolic pressures to differ?
4.49 mmHg
8.56 mmHg
0.07 mmHg
0.56 mmHg