The correlation between two variables is -0.63 for a sample of 20 observations. What is the computed value of the test statistic?
A) 3.442
B) -0.63
C) -3.442
D) -1.26

Question

Quizplus · Accepted Answer

To compute the test statistic for a correlation coefficient, we use the formula:

t = r√[(n-2)/(1-r^2)]

where r is the correlation coefficient, n is the sample size.

Plugging in the values, we get:

t = -0.63√[(20-2)/(1-(-0.63)^2)]
t = -0.63√(18/0.6051)
t = -0.63√29.7272
t = -0.63(5.4574)
t = -3.4418

So, the computed value of the test statistic is -3.442, which is option C.

The Correlation Between Two Variables Is -0