# Answer on Statistics and Probability Question for Dion

Question #17338

If the standard deviation of a national accounting examination is 900, how large a sample is needed to estimate the true mean score within 5 points with 99% confidence?

Expert's answer

Variance = 900

Standard deviation = 30

z(alpha) = 2.575

error = 5

n = ( z(alpha) * SD /error)² = ( 2.575 * 30 / 5 )² = 238.7025

sample of 239 is needed.

Standard deviation = 30

z(alpha) = 2.575

error = 5

n = ( z(alpha) * SD /error)² = ( 2.575 * 30 / 5 )² = 238.7025

sample of 239 is needed.

Need a fast expert's response?

Submit orderand get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

## Comments

## Leave a comment