Asked by krissy

sample size needed with a mean of 100,standard deviation of 20 for the the population of normal adults an iq range to fall between 2 iq points with 95% confidence interval
Answered by PsyDAG
95% = mean ± 1.96 SEm

SEm = SD/√n

2 = 1.96 * 20/√n

Solve for n.