Question

A nurse is interested in whether there is a relationship between daily levels of stress and likelihood of a heart attack. The stress scores (predictor variable) and risk of heart attack values (criterion variable) from a small sample of participants are depicted below.

Stress Score                                Risk of Heart Attack
(Higher values = more stress)     (Higher values = greater risk)
     
  8                                                     3
      4                                                     8
      1                                                     8
      3                                                     2

What is the Pearson's r value?

Answer 1

Use excel

First of all, enter the stress score in column A from A1 to A4 and risk of heart attack data in column B from B1 to B4

Now, use CORREL function to find the correlation coefficient r

r = CORREL(array1,array2)

r =CORREL(A1:A4,B1:B4)

r = -0.4951 (4 decimals)