AP Statistics Chapter 3 Review

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. Approximately 95% of molds filled by this machine will hold weights in what interval?

• 1084 to 1216 pounds 

• 1106 to 1150 pounds 

• 1106 to 1194 pounds 

• 1128 to 1172 pounds

The Empirical (68-95-99.7) Rule can only be applied when a curve is....

• Normally Distributed

• Uniform

• Has no Mean

• Has both mean and standard deviation regardless of shape

If heights of 3rd graders follow a normal distribution with a mean of 52 inches and a standard deviation of 2.5 inches, what is the z score of a 3rd grader who is 47 inches tall?

• -5

• -2

• 2

• 5

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Find the Z-score.

Mean = 21

Standard Deviation: 1.3

x = 22

• 0.77

• 5.33

• 1.07

• 1.26

• 15.87%

• 15.39%

• 9.68%

• 84.61%

Find the value for 
P(Z > 1.78)

• 0.0376

• 0.0375

• 0.0446

• 0.2420

Find the value for 
P(Z < -0.386)

• 0.3498

• 0.3520

• 0.3501

• 0.6502

Z > 0.84 = %

Z > 0.06 = %