SOLUTION: Suppose that, for a certain mathematics class, the scores are normally distributed with a mean of 75 and a standard deviation of 9. The teacher wishes to give A's to the top 6% of

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Question 1169244: Suppose that, for a certain mathematics class, the scores are normally distributed with a mean of 75 and a standard deviation of 9. The teacher wishes to give A's to the top 6% of the students and F's to the bottom 6%. The next 16% in either direction will be given B's and D's, with the other students receiving C's. Find the bottom cutoff for receiving an A grade. (You may need to use the standard normal distribution table. Round your answer to the nearest whole number.)
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
The top 6% would be the 94th percentile
z(0.94)=1.55
z=(x-mean)/sd
1.55=(x-75)/9
13.99=x-75
x=88.99 or 89