Question

A hypothesis test is conducted at the .05 level of significance to test whether or not the population correlation is zero. If the sample consists of 25 observations and the correlation coefficient is 0.60, then what is the computed value of the test statistic?

Answer 1

Answer:

Th computed value of the test statistic is 3.597

Step-by-step explanation:

The null and the alternative hypothesis is as follows:

Null Hypothesis:

$\mathbf{H_o:}$ the population correlation coefficient is equal to zero

$\mathbf{H_a:}$ the population correlation coefficient is not equal to zero

The test statistics for Pearson correlation coefficient is thus computed as :

$t =\dfrac{r \sqrt{(n-2)}} { \sqrt{(1-(r)^2)} }$

where;

r = correlation coefficient = 0.60

n = sample size = 25

So;

$t =\dfrac{0.60 \sqrt{(25-2)}} { \sqrt{(1-(0.60)^2)} }$

$t =\dfrac{0.60 \sqrt{(23)}} { \sqrt{(1-0.36} }$

$t =\dfrac{0.60 *4.796} {0.8}$

t = 3.597

Comparing to a critical value of t (23 degrees of freedom two-tailed value) = 2.069

Decision Rule:

Since computed value of t is greater than the critical value of t; We reject the null hypothesis and accept the alternative hypothesis.

Conclusion:

We conclude that the population correlation coefficient significantly differs from 0 at 5% (0.05) level of significance.