A researcher collects 25 data points that yield a mean of 8.164 and a standard deviation (based on N - 1) of 2.237.If the researcher is comparing the sample to a population mean of 9.2 using a single-sample t test, what would be the effect size?
A) -0.60
B) -0.46
C) 0.46
D) 0.68

Question

Quizplus · Accepted Answer

To calculate the effect size, we use the formula Cohen's d = (sample mean - population mean) / sample standard deviation. Plugging in the values, we get Cohen's d = (8.164 - 9.2) / 2.237 = -0.46, so the correct answer is B.

A Researcher Collects 25 Data Points That Yield a Mean