Name:    Unit 07-05 - Sample Quiz: Normal Distributions

Multiple Choice
Identify the choice that best completes the statement or answers the question.

1.

 The heights of adult women are normally distributed with a mean of 62.5 inches and a standard deviation of 2.5 inches. Determine between what two heights 68.2% of adult women will fall.
 a. between  52.5 and 725 c. between 57.5 and 67.5 b. between 60 and 65 d. between 55 and 70

2.

For a standard normal distribution, what is the mean and standard deviation?

 a. c. b. d.

3.

 Find the area between the z-scores, z = 1 and z = 2.
 a. 2.3% c. 34.1% b. 15.6% d. 47.7%

4.

The D.O.T. collected data for a particular stretch of I-85 and found that the average speed was 70 mph  with a standard deviation of  15 mph and the distribution is approximately normally distributed. The actual Speed Limit for the stretch of road is a maximum of 70 mph and minimum of 40 mph. What percentage of drivers actually drive between 40mph and 70 mph?

 a. 15.9% c. 84.1% b. 47.7% d. 97.7%

5.

 Determine the area under the normal curve between the z-scores, z = -0.8 and 1.6 as shown in the graph.
 a. 0.267 c. 0.733 b. 0.684 d. 0.786

6.

If a set of data is normally distributed, what percent of the data has a z-score that is greater than ?

 a. 30.9% c. 42.1% b. 35.2% d. 48.4%

7.

 A company’s mean salary is \$65,000 with a standard deviation of \$6,000. What is the probability that an employee makes between \$70,000 and \$80,000?(Hint: First find the z-score for x = 70000 and x = 8000.)

 a. 0.8039 c. 0.5643 b. 0.9938 d. 0.1961

8.

 The weight of a specific type of male monkey is normally distributed with a mean of 15 pounds and a standard deviation of 3 pounds. What is the z-score for a monkey weighing 19 pounds?
 a. c. b. d.

9.

 Using a Standard Normal Distribution, what z-score has an area of .892 ?
 a. 0.108 c. 1.237 b. 0.814 d. 1.654

10.

A study was being conducted about birth weights of babies at a local hospital and found the average to be 7.6 pounds with a standard deviation of 1.3 pounds (the distribution was approximately normal). Many pre-mature births weights are in the lowest 1% of births.  What would be the birth weight associated with the lowest 1%?
( Hint: First use the invNorm command in your calculator to find the z-score and then solve for x to find the birth rate)

 a. 2.32 pounds c. 4.58 pounds b. 3.98 pounds d. 4.87 pounds