A correlation is computed using data from 28 people.What is the critical cutoff for a two-tailed hypothesis test with a p level of 0.05?
A) 0.317
B) 0.374
C) -0.317 and 0.317
D) -0.374 and 0.374

Question

Quizplus · Accepted Answer

Since the p level is 0.05 for a two-tailed hypothesis test, we need to divide by 2 to get a significance level of 0.025 for each tail. With 28 degrees of freedom, looking at a t-distribution table, the critical t value for 0.025 level of significance is 2.048. Multiplying this by the standard error of the correlation coefficient for a sample size of 28, which is 0.374, we get the critical cutoff of 0.765 (2.048 x 0.374). Thus, the range for the critical cutoff is -0.765 to +0.765 or -0.374 to +0.374 approximately (since we are dealing with limited precision in the values of the standard error and t-value). Therefore, the answer is D.

A Correlation Is Computed Using Data from 28 People