Question

Suppose that Professor Carrol has a policy of giving A's to the top 10% of the score of her final, regardless of the actual scores. If the distribution of scores on her final turn out to be normal with mean 69 and standard deviation 9, how high does her score have to be to earn an A?

Answer 1

This is a look-up problem. Find the z-score that puts 10% in the right tail.

Answer 2

So, what's the answer?

Answer 3

You tell me. What z-score leaves 10% in the right tail of the Normal Distribution?

Answer 4

What happens after i find the z-score

Answer 5

Compare it to \(\dfrac{Score - 69}{9}\) and solve for "\(Score\)".