A researcher conducts a repeated-measures study comparing two treatment conditions with a sample of n = 25 participants and obtains a t-statistic of t = 2.21. Which of the following is the correct decision for a two-tailed test?

A. Reject the null hypothesis with? =.05 but fail to reject with? =.01.

B. Reject the null hypothesis with either? =.05 or? =.01.

C. Fail to reject the null hypothesis with either? =.05 or? =.01.

D. cannot determine the correct decision without more information

Answer: A

Step-by-step explanation:

Since the number of samples, n is 25, we would determine the degree of freedom, df

df = n - 1 = 25 - 1

df = 24

Given the test statistic = 2.21 and the test is a two-tailed test, we would determine the probability value using the t test calculator.

At significant level of 0.05,

P value = 0.037

At significant level of 0.01,

p value = 0.037

The decision rule is that:

We would reject the null hypothesis if significant level is > p value

Therefore,

A. Reject the null hypothesis with alpha = 0.05 but fail to reject with alpha = 0.01