SOLUTION: A teacher says that the top 10% of the class received an A on the last test. The scores were normally distributed with mean 65 and standard deviation 20. Find the minimum score req

Algebra ->  Probability-and-statistics -> SOLUTION: A teacher says that the top 10% of the class received an A on the last test. The scores were normally distributed with mean 65 and standard deviation 20. Find the minimum score req      Log On


   

Question 1026130: A teacher says that the top 10% of the class received an A on the last test. The scores were normally distributed with mean 65 and standard deviation 20. Find the minimum score required to get an A.
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
P%28X%3E=beta%29+=+0.10
<==>
By referring to a table of standard normal values, we find that
%28beta+-+65%29%2F20+=+1.285
==> beta+=+65%2B20%2A1.285+=+90.7,
==> the minimum score to get an A is 91.