Posted by zac on .
A random sample of 100 students from a high school was selected. If a 98% confidence interval estimate for the mean age of students is calculated to be 14.2511 to 14.9489, then the standard deviation of the sample mean is?

statistics 
Kuai,
2E + 14.2511 = 14.9489
2E = 0.6978
E = 0.3489
E = za/2 * s /sqrt(n))
.3489 = 2.33s/10
. 3489 = .233s
s = 1.49742
Standard deviation. = 1.49742