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4. Suppose a test of math anxiety was given to 500 people. The scores are assumed...

4. Suppose a test of math anxiety was given to 500 people. The scores are assumed to be from a normally distributed population. The mean of the test was 50, with a standard deviation of 8. The higher the score, the higher the math anxiety 10 points.

a. What percentage is expected to score below 30?

b. What score corresponds to the 65th percentile?

c. What percentage is expected to score between 30 and 40?

d. If the maker of the test claims that anyone scoring above the 72nd percentile is pathologically anxious, what score must one have on the test to be considered to have a pathology?

e. How many people in this sample then can we expect to have a serious pathology?

Math   Statistics-And-Probability   
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