Question

The same sample of 25 seniors from the urban school district with the mean and standard deviation N(450, 100). A 95% confidence interval for µ for the population of seniors with a margin of error of ± 25 is used. What is the smallest sample size we can take to achieve this same margin of error?

26

45

50

62

69

Answer 1

I have some notes here that might help you answer the problem in your own:

The formula to calculate a minimum sample size is as follows:

n = [z*s/E]^2 

Where n is the sample size, z is the z value for the level of confidence chosen, s is the estimated standard deviation and E is the allowable error. 

I hope my answer has come to your help. God bless and have a nice day ahead!