the average math sat score is 500 with a standard deviation of 100. a particular high school claims that its students have usually high math SAT scores a random sampel of 50 students from this school was selected, and the mean math sat score was 530 . Is the high school justified in its claim?

Question

the average math sat score is 500 with a standard deviation of 100. a particular high school claims that its students have usually high math SAT scores a random sampel of 50 students from this school was selected, and the mean math sat score was 530 . Is the high school justified in its  claim?

PsyDAG · Answer

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. Is it smaller than your alpha error?