OpenStax, Statistics §6.2 Using the Normal Distribution · Exercise 24 · Statistics · Normal distribution

Using the Normal Distribution · Exercise 24

IQ is normally distributed with a mean of 100 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual.

(a) X ~ _____ (_____, _____)
(b) Find the probability that the person has an IQ greater than 120. Include a sketch of the graph, and write a probability statement.
(c) MENSA is an organization whose members have the top 2 percent of all IQs. Find the minimum IQ needed to qualify for the MENSA organization. Sketch the graph, and write the probability statement.
(d) The middle 50 percent of IQs fall between what two values? Sketch the graph, and write the probability statement.

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OpenStax, Statistics · §6.2 Using the Normal Distribution · Exercise 24

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