DrFillipe Is Investigating the Effects of Vitamin B Consumption on Stress

Multiple Choice

Dr.Fillipe is investigating the effects of vitamin B consumption on stress levels.He randomly gives half of his participants a daily dose of vitamin B for one month while the other half takes a sugar pill.Each day,the participants provide a saliva sample to measure stress hormones.If Dr.FIllipe wanted to determine whether the vitamin B group had significantly lower levels of stress hormones compared to the sugar pill group,which of the following pieces of information would he NOT need to know?

A) the number of participants in each group
B) the mean levels of stress hormones of each group
C) the standard deviation for stress hormone levels of each group
D) the correlation coefficient of each group