statistics
posted by looking for someone to varify my work please .
Question:
A standard placement test has a mean of 105 and a standard deviation of ó = 13. Determine the minimum sample size if we want to be 99% certain that we are within 3 points of the true mean.
Answer:
N = ( zc ó/E)^2
= (2.575 x 13/3)^2
= 121
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