A Researcher Reports That the Mean Time It Takes to Complete

Multiple Choice

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?

A) d = 0.05; small effect size
B) d = 0.50; medium effect size
C) d = 1.05; large effect size
D) there is not enough information to answer this question