Hi

Wanting help with dissertation - performing meta analysis as part of my medical degree - hope I am posting on correct line.

Need to work out Standard deviation from confidence interval for both placebo and treatment group think the equation is:

SD = SQRT of N x (upper limit - lower limit)/3.92.

CI = 95%

Is this correct?

Treatment group: Number = 52 - upper limit 55 - lower limit 24.3

Control group: Number 57 - upper limit 28.1 - lower limit 13.7

So are the answers: Treatment = 56

Control = 28

Any help would be great

Cheers