Normal Distribution Practice

If a given data point is smaller than the mean, the value of z is:

• Not enough information

• Negative

• Positive

• 0

If a given data point is the same as the mean, the value of z is:

• Not enough information

• Positive

• Negative

• 0

What's the probability x > 17?

(Mean = 15, Standard dev = 3)

• 0.7486

• 0.7454

• 0.2514

• 0.2546

What's the probability of the gray area?

(Mean = 55, Standard dev = 2.5)

• 0.815

• 0.8413

• 0.8641

• 0.8389

What's the probability of x < 13 ?

(Mean = 20, Standard dev = 6.5)

• 0.1423

• 0.1401

• 0.0446

• 0.0359

What's the probability of the highlighted area?

(Mean = 100, Standard dev = 10) Choose closest values if just using the graph percents.

• 0.9772

• 0.0228

• 0.1587

• 0.0062

What's the probability of 49 < x < 51 ?

(Mean = 50, Standard dev = 6.5)

• 0.1192

• 0.1251

• 0.1587

• 0.0875

Based on the graph, who has the highest IQ?

• You

• Me

• Both have the same

• Not enough information

If you had to guess the probability of the gray area, which would you choose?

• 0.25

• 0.16

• 0.6

• 0.8

Which gray area shows a probability closer to 0.5?

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