Question

A researcher reports that the mean time it takes to complete an experimental task is 1.4 ± 8.0 (M ± SD) s. If the null hypothesis was that the mean equals 1.0, then what is the effect size for this test using estimated Cohen’s d? Group of answer choices

Answer 1

Answer:

The Cohen's d effect size is 0.05.

Step-by-step explanation:

The Cohen's d effect size is a numerical value that indicates the standardized difference between two means.

It is provided that the mean time to complete an experimental task reported by the researcher is,

$(\bar x\pm s)=(1.4\pm8.0)$

Since the standard deviation of the population is not provided we will use a one-sample t - test to perform the analysis.

The formula of Cohen's d effect size in case of one-sample t - test is:

$d=\frac{\bar x-\mu}{s}$

Compute the value of Cohen's d effect size as follows:

$d=\frac{\bar x-\mu}{s}=\frac{1.4-1.0}{8}=\frac{0.4}{8}=0.05$

Thus, the Cohen's d effect size is 0.05.