# Coefficient of variation, Normal probability

Lind Problems Sets

Chapter 4 Exercise 22

22. The spread in the annual prices of stocks selling for under $10 and the spread in prices of those selling for over $60are to be compared. The mean price of the stocks selling for under $10 is $5.25 and the standard deviation $1.52. The mean price of those stocks selling for over $60 is $92.50 and the standard deviation $5.28.

1. Why should the coefficient of variation be used to compare the dispersion in the prices?

2. Compute the coefficients of variation. What is your conclusion?

Chapter 5, Exercise 66 a,b,e

66. A survey of undergraduate students in the School of Business at Northern University revealed the following regarding the gender and majors of the students:

Major

Gender Accounting Management Finance Total

Male 100 150 50 300 Female 100 50 50 200

Total 200 200 100 500

A. What is the probability of selecting a female student?

B. What is the probability of selecting a finance or accounting major?

E. What is the probability of selecting an accounting major, given that the person selected is a male?

Chapter 6 Exercise 6

6. The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. What is the expected number of admissions for the fall semester?

Compute the variance and the standard deviation of the number of admissions.

Admissions Probability

1,000 .6

1,200 .3

1,500 .1

Chapter 7, Exercise 44

44. The number of passengers on the Carnival Sensation during one-week cruises in the Caribbean follows the normal distribution. The mean number of passengers per cruise is 1,820 and the standard deviation is 120.

1. What percent of the cruises will have between 1,820 and 1,970 passengers?

2. What percent of the cruises will have 1,970 passengers or more?

3. What percent of the cruises will have 1,600 or fewer passengers?

4. How many passengers are on the cruises with the fewest 25 percent of passengers?

#### Solution Preview

22)

1) coefficient of variation is the percentage variation in the mean ,standard deviation being considered as the total variation in the mean .

2)

under $10 stock, CV = 100*1.52/5.25 = 28.95

over $60 stock, CV = 100*5.28/92.5 = 5.7

over $60 stock is more consistent

66)

a) probability of selecting a female student = 200/500

b) probability of selecting ...

#### Solution Summary

Coefficient of Variation , Probability of normal distribution