SOLUTION: SAT scores are distributed with a mean of 1,500 and a standard deviation of 286. You are interested in estimating the average SAT score of first year students at your college. If

Algebra ->  Probability-and-statistics -> SOLUTION: SAT scores are distributed with a mean of 1,500 and a standard deviation of 286. You are interested in estimating the average SAT score of first year students at your college. If      Log On


   



Question 1182661: SAT scores are distributed with a mean of 1,500 and a standard deviation of 286.
You are interested in estimating the average SAT score of first year students at your college.
If you would like to limit the margin of error of your confidence interval to 25 points with a 90 percent confidence, how many students should you sample?
(Round up to a whole number of students)

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
this is a z-CI
error = z(0.975)*sigma/sqrt(n)
25=1.645*286/sqrt(n)
square both sides
625=221342.02/n
n=354.14 or 355