Posted by Anige on Sunday, June 5, 2011 at 1:25pm.
A 95% confidence interval for a population mean was reported to be 23,100 to 24,900. If the sample standard deviation is 5,808.26, what sample size was used in this study?

statistics  MathGuru, Monday, June 6, 2011 at 8:13pm
Formula:
CI95 = mean + or  (1.96)(sd)/√n
Mean = (23100 + 24900)/2 = 24000
Standard deviation = 5808.26
CI95 = 24000 + or  900 > gives you confidence interval of 23100 to 24900.
Therefore:
900 = (1.96)(sd)/√n
900 = (1.96)(5808.26)/√n
Solve for n. Round n to whole number.
I hope this will help.