The distribution of raw scores on a chemistry final is approximately normal with mean of about 50 and standard deviation of about 10.

11. The distribution of raw scores on a chemistry final is approximately normal with mean of about 50 and

standard deviation of about 10. What is the probability that a student will have a raw score that is

more than 45?

a. 0.7238

b. 0.3085

c. 0.4500

d. 0.6915

e. none of these

12. Which of the following is NOT a property of the Normal distribution?

a. the area under the Normal density curve must add up to 1

b. the mean is equal to the median, and both lie directly in the middle of the curve

c. approximately 5% of the data lies OUTSIDE 2 standard deviations from the mean

d. approximately 68% of the data lies WITHIN 2 standard deviations from the mean

e. all are correct

13. A normal density curve has which of the following properties?

a. It is symmetric.

b. It has a peak centered above its mean.

c. The spread of the curve is proportional to the standard deviation.

d. Only a and b

e. all of these above

3

14. A continuous random variable may assume

a. any value in an interval or collection of intervals

b. only integer values in an interval or collection of intervals

c. only fractional values in an interval or collection of intervals

d. only the positive integer values in an interval

e. none of these

15. A description of the distribution of the values of a random variable and their associated probabilities is

called a

a. probability distribution

b. random variance

c. random variable

d. expected value

e. none of these