Statistics Confidence Interval

Question

In a randomized comparative experiment on the effect of dietary calcium on blood pressure, researchers divided 48 healthy white males at random into two groups. One group received calcium; the other, a placebo. At the beginning of the study, the researchers measured many variables on the subjects. The paper reporting the study gives 114.7 and s = 8.8 for the seated systolic blood pressure of the 24 members of the placebo group.

 

Give a 95% confidence interval for the mean blood pressure in the population from which the subjects were recruited is

Answer 1

the error margin is 1.96*8.8/sqrt(24) = 3.520733257-

( 111.19266743, 118.220733257-)