Question

Large group of students took a test in English and the final grades have a mean of 75 and a standard deviation of 8. If we can approximate the distribution of these grades by a normal distribution. What percentage of the students
(ii) Should pass the test (grades >= 60)
(iii) Should fail the test(grades <60?

Answer 1

Z = (score-mean)/SD

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.

Answer 2

An urn contains7 white balls and 3 yellow balls. If Tim chooses 8 balls at random from the urn, what is the probability that he will select6 white balls and 2 yellow balls? Round your answer to decimal places.