Probability and IQ Assessment

The video tutorial explains how to calculate probabilities for different IQ scores using a normal distribution. It covers finding the probability of having an IQ greater than 90 and less than 120, and extends these calculations to determine how many people in a sample would have an IQ less than 105 or greater than 135. The tutorial uses an online normal distribution calculator to demonstrate these calculations, emphasizing the conversion of probabilities to percentages and rounding rules.

What is the mean IQ score in the normal distribution discussed?

• 90

• 100

• 120

• 110

What is the probability of a person having an IQ greater than 90?

• 0.548

• 0.658

• 0.748

• 0.848

How is the probability of an IQ greater than 90 represented?

• P(X > 90)

• P(X = 90)

• P(X < 90)

• P(X ≤ 90)

What is the probability of a person having an IQ less than 120?

• 0.909

• 0.809

• 0.609

• 0.709

How is the probability of an IQ less than 120 represented?

• P(X > 120)

• P(X < 120)

• P(X ≥ 120)

• P(X = 120)

In a sample of 1,200 people, how many are expected to have an IQ less than 105?

• 957

• 857

• 757

• 657

What is the probability of having an IQ less than 105?

• 0.831

• 0.731

• 0.931

• 0.631

In a sample of 600 people, how many are expected to have an IQ greater than 135?

• 16

• 36

• 6

• 26

What is the probability of having an IQ greater than 135?

• 0.030

• 0.040

• 0.020

• 0.010

How is the probability of an IQ greater than 135 represented?

• P(X ≤ 135)

• P(X < 135)

• P(X = 135)

• P(X > 135)