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,
[tex](\bar x\pm s)=(1.4\pm8.0)[/tex]
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:
[tex]d=\frac{\bar x-\mu}{s}[/tex]
Compute the value of Cohen's d effect size as follows:
[tex]d=\frac{\bar x-\mu}{s}=\frac{1.4-1.0}{8}=\frac{0.4}{8}=0.05[/tex]
Thus, the Cohen's d effect size is 0.05.
