Chapter 10, Problem 1CQQ

The exercises arc based on the following sample data obtained from different second-year medical students who took blood pressure measurements of the same person (based on data from Marc Triola, MD).

Systolic	138	130	135	140	120
Diastolic	82	91	100	100	80

1. If you plan to use a 0.05 significance level in a test of a correlation between the systolic and diastolic readings, what are the critical values of r?

To determine

To find: The critical values of r.

Answer to Problem 1CQQ

The critical value of r is±0.878.

Explanation of Solution

Given info:

The data shows that the measurements of systolic and diastolic blood pressures. The level of significance is $\alpha =0.05$.

Calculation:

Critical value:

The degrees of freedom (n) is 5. From the TABLE A-6 “Critical Values of the Pearson Correlation Coefficient r”, the critical value for 5 degrees of freedom and $\alpha =0.05$ level of significance is ±0.878.

Conclusion:

Thus, the critical value of r is±0.878.