# statistics probability

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Alice earned a score of 940 on an IQ test.The mean test score was 850 with a standard deviation of 100.(Assume that test scores are normally distributed).

Q1a).What proportion of students had a higher score than alice?

Qb)Find the score exceeded by 2.5% of the students.

• statistics probability -

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.

• statistics probability -

The scores on a test are normally distributed with a mean of 140 and a standard deviation of 28, what is the score that is one standard deviation above the mean?

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