Lesson 5.6 Checkpoint

The distribution of heights of adult American men can be modeled by a normal distribution with mean μ = 69 inches and standard deviation σ = 2.5 inches. Let X = the height (in inches) of a randomly selected adult American man. Use the 68–95–99.7 rule to approximate: P(X > 74)

(LT 5.6.1 #1)

• 0.025

• 0.68

• 0.95

• 0.0228

The distribution of heights of adult American men can be modeled by a normal distribution with mean μ = 69 inches and standard deviation σ = 2.5 inches. Let X = the height (in inches) of a randomly selected adult American man. Use the 68–95–99.7 rule to approximate: The probability that the man has a height between 64 and 71.5 inches

(LT 5.6.1 #2)

• 0.815

• 0.68

• 0.95

• 0.8186

Cholesterol levels for 14-year-old boys can be modeled by a normal distribution with mean 170 mg/dl and standard deviation 30 mg/dl. Let X = the cholesterol level (in milligrams per deciliter) of a randomly selected 14-year-old boy. Use the 68–95–99.7 rule to approximate: The probability that his cholesterol level is less than 140 mg/dl.

(LT 5.6.1 #3)

• 0.16

• 0.68

• 0.997

• 0.1587

Cholesterol levels for 14-year-old boys can be modeled by a normal distribution with mean 170 mg/dl and standard deviation 30 mg/dl. Let X = the cholesterol level (in milligrams per deciliter) of a randomly selected 14-year-old boy. Use the 68–95–99.7 rule to approximate: P(200 ≤ X ≤ 230).

(LT 5.6.1 #4)

• 0.135

• 0.68

• 0.997

• 0.1359

Using Technology,

Find the probability that Z is greater than 1.53

(LT 5.6.2 #1)

• 0.0630

• 0.9370

• 0

• 1

Using Technology,

Find P(−1.66 ≤ Z ≤ 2.85)

(LT 5.6.2 #2)

• 0.9494

• 0.0485

• 0.0022

• 0

Use Technology to find the value of z for which P(Z > ____ ) = 0.34.

(LT 5.6.3 #1)

• z = 0.41

• z = -0.41

• 0.3669

• None of the above