Question

The following sample data were obtained from different second-year medical students who took blood pressure measurements of the same person. Conduct a formal hypothesis test to test for a linear correlation between the systolic and diastolic readings. Use a 0.05 significance level.

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

What is the value of r? Round to 3 decimal places.

Answer 1

Systolic(x)	Diastolic(y)
138	82
130	91
135	100
140	100
120	80

The formula for correlation is

= 0.585

Our null and alternative hypothesis are

against

where denotes the population correlation coefficient

The test statistic is

= 1.249

The P-value is

= 0.15 x 2

= 0.3

Since P-value > (= 0.05) we have failed to reject the null hypothesis at 0.05 level of significance.

Thus we cannot claim that there is a linear correlation between systolic and diastolic readings.