Question

A journal article states that “Students scored higher at the post-test than at the pre-test, t (29) = 3.4, p <0.05”.

(1)Was this result statistically significant?

(2)If the researcher had conducted the test by hand, what critical value would they have used to decide whether the outcome was significant? Assume a two-tailed test

(3) What is the value of r² ?

Answer 1

(1)Was this result statistically significant?

Yes the result is statistically significant because p-value is less than 0.05.

(2)If the researcher had conducted the test by hand, what critical value would they have used to decide whether the outcome was significant? Assume a two-tailed test

given degrees of freedom df = 29

critical value for two-tailed test with alpha = 0.05 is t0.025,29 = 2.045.

Since the test statistic  t (29) = 3.4 > t0.025,29 = 2.045. Yes the result is statistically significant.

(3) What is the value of r2 ?

r2 = = (3.42)/(3.42+29) = 0.285