# Stanford-Binet IQ Test Scores: Distribution, z score, probability

Stanford-Binet IQ Test scores are normally distributed with a mean score of 100 and a standard deviation of 16.

a. Sketch the distribution of Stanford -Binet IQ test scores.

b. Write the equation that gives the z score corresponding to a Stanford-Binet IQ test score. Sketch the distribution of such z scores.

c. Find the probability that a randomly selected person has an IQ test score.

1. Over 140

2. Under 88

3. Between 72 and 128

4. Within 1.5 standard deviations of the mean.

d. Suppose you take the Stanford-Binet IQ Test and receive a score of 136. What percentage of people would receive a score higher than yours?

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#### Solution Preview

Parts (a)-(b): See attached picture.

Part (c)

1. P(X > 140) = P(z > (140-100)/16) = ...

#### Solution Summary

The expert examines the Standford-Binet IQ test scores for distribution, z scores and probability.