1. What is the area under the normal curve between z = 0.0 and z = 1.79?

a. 0.4633

b. 0.0367

c. 0.9599

d. 0.0401

Answer: _____

2. The mean score of a college entrance test is 500; the standard deviation is 75. The scores are normally distributed. What percent of the students scored below 320?

a. About 50.82%

b. About 34.13%

c. About 7.86%

d. About 0.82%

Answer: _____

3. A new extended-life light bulb has an average life of 750 hours, with a standard deviation of 50 hours. If the life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 hours and 900 hours?

a. 95%

b. 68%

c. 34%

d. 99.47%

Answer: _____

4. The weight of cans of fruit is normally distributed with a mean of 1,000 grams and a standard deviation of 50 grams. What percent of the cans weigh 860 grams or less?

a. 0.0100

b. 0.8400

c. 0.0026

d. 0.0001

Answer: _____

5. A large manufacturing firm tests job applicants. Test scores are normally distributed with a mean of 500 and a standard deviation of 50. Management is considering placing a new hire in an upper-level management position if the person scores in the upper sixth percent of the distribution. What is the lowest score a new hire must earn to qualify for a responsible position?

a. 50

b. 625

c. 460

d. 578

Answer: _____

6. The average score of 100 students taking a statistics final was 70, with a standard deviation of 7. Assuming a normal distribution, what is the probability that a student scored 90 or higher?

a. 0.4979

b. 0.0021

c. 0.9979

d. 2.86

Answer: _____

7. The mean of a normal probability distribution is 60 and the standard deviation is 5. The percent of observations that are between 50 and 70 is ______.

Answer:

8. The proportion of the area under a normal curve that is to the left of z = 1.40 is _______.

Answer:

9. The proportion of the area under a normal curve that is to the right of z = -1.71 is _______.

Answer:

10. The weight of a bag of corn chips is normally distributed with a mean of 22 ounces and a standard deviation of 0.5 ounces. The probability that a bag of corn chips weighs more than 23 ounces is ____.

Answer:

11. Two business major students, in two different sections of an economics class, were comparing test scores. The following shows the sections' mean and standard deviation. The student in section 2 scored 75. The student's z score would be _____.

Answer:

12. A sample of 500 part-time students revealed that their annual incomes were normally distributed with a mean income of $30,000 and a standard deviation of $3,000. The number of students who earned more than $36,000 was ______.

Answer:

13. From past history, the scores on a statistics test are normally distributed with a mean score of 70 and a standard deviation of 5. To earn a "C" on the test, a student must be in the top 25% of the class. A student would need to score at least ______ to receive a "C" grade.

Answer: