homework

CHAPTER 5 EXERCISE 4

A large company must hire a new president. The Board of Directors prepares a list of five candidates, all of whom are equally qualified. Two of these candidates are members of a minority group. To avoid bias in the selection of the candidate, the company decides to select the president by lottery.

a.

What is the probability one of the minority candidates is hired? (Round your answer to 1 decimal place.)

  Probability

b.

Which concept of probability did you use to make this estimate?

CLASSICAL

EMPIRICAL

RANDOMNESS

UNIFORMITY

INFERNENCE

CHAPTER 5 EXERCISE 14

The chair of the board of directors says, "There is a 50% chance this company will earn a profit, a 30% chance it will break even, and a 20% chance it will lose money next quarter."

a.

Use an addition rule to find the probability the company will not lose money next quarter. (Round your answer to 2 decimal places.)

(Click to select) =

0.5 + 0.2

0.5 - 0.2

0.5 + 0.3

0.3 + 0.2

1.0 - 0.2

b.

Use the complement rule to find the probability it will not lose money next quarter. (Round your answer to 2 decimal places.)

(Click to select) =

0.3 + 0.2

1.0 - 0.2

0.5 + 0.2

0.5 - 0.2

0.5 + 0.3

A National Park Service survey of visitors to the Rocky Mountain region revealed that 50% visit Yellowstone Park, 40% visit the Tetons, and 35% visit both.

a.

What is the probability a vacationer will visit at least one of these attractions? (Round your answer to 2 decimal places.)

  Probability

 ________

b.

What is the probability .35 called?

(Click to select)

Exclusive

Joint

Complement

c.

Are the events mutually exclusive?

(Click to select)

Sometimes

No

Yes

P(A1) = .20, P(A2) = .40, and P(A3) = .40.  P(B1|A1) = .25. P(B1|A2) = .05, and P(B1|A3) = .10.

Use Bayes' theorem to determine P(A3|B1). (Round your answer to 4 decimal places.)

  P(A3|B1)

 _____________

Solve the following:

a.

b.

   9P 3

c.

  7C 2

Which of these variables are discrete and which are continuous random variables?

a.

 The number of new accounts established by a salesperson in a year.

  (Click to select)

Continuous

Discrete

b.

 The time between customer arrivals to a bank ATM.

  (Click to select)

Discrete

Continuous

c.

 The number of customers in Big Nick’s barber shop.

  (Click to select)

Continuous

Discrete

d.

 The amount of fuel in your car’s gas tank.

  (Click to select)

Continuous

Discrete

e.

 The number of minorities on a jury.

  (Click to select)

Continuous

Discrete

f.

 The outside temperature today.

  (Click to select)

Continuous

Discrete

CHAPTER 6 EXERCISE 14

CHAPTER 6 EXERCISE 20

In a binomial distribution, n = 12 and π = .60.

a.

Find the probability for x = 5? (Round your answer to 3 decimal places.)

  Probability

b.

Find the probability for x ≤ 5? (Round your answer to 3 decimal places.)

  Probability

c.

Find the probability for x ≥ 6? (Round your answer to 3 decimal places.)

  Probability

CHAPTER 6 EXERCISE 26

A population consists of 15 items, 10 of which are acceptable.

In a sample of four items, what is the probability that exactly three are acceptable?

Assume the samples are drawn without replacement. (Round your answer to 4

decimal places.)

  Probability

CHAPTER 7 EXERCISE 4

According to the Insurance Institute of America, a family of four spends between $400 and $3,800 per year on all types of insurance. Suppose the money spent is uniformly distributed between these amounts.

a.

What is the mean amount spent on insurance?

  Mean

$  

b.

What is the standard deviation of the amount spent? (Round your

answer to 2 decimal places.)

  Standard deviation

$  

c.

If we select a family at random, what is the probability they spend less

than $2,000 per year on insurance per year? (Round your answer to 4

decimal places.)

  Probability

d.

What is the probability a family spends more than $3,000 per year?

(Round your answer to 4 decimal places.)

  Probability

CHAPTER 7 EXERCISE 10

The mean of a normal probability distribution is 60; the standard deviation is 5.

(Round your answers to 2 decimal places.)

a.

About what percent of the observations lie between 55 and 65?

  Percentage of observations

%  

b.

About what percent of the observations lie between 50 and 70?

  Percentage of observations

%  

c.

About what percent of the observations lie between 45 and 75?

  Percentage of observations

%  

CHAPTER 7 EXERCISE 14

A normal population has a mean of 12.2 and a standard deviation of 2.5.

a.

 Compute the z value associated with 14.3. (Round your answer to 2 decimal

places.)

  Z

b.

 What proportion of the population is between 12.2 and 14.3? (Round

your answer to 4 decimal places.)

  Proportion

c.

 What proportion of the population is less than 10.0? (Round your answer

to 4 decimal places.)

  Proportion

A normal population has a mean of 80.0 and a standard deviation of 14.0.

a.

Compute the probability of a value between 75.0 and 90.0. (Round

intermediate calculations to 2 decimal places. Round final answer

to 4 decimal places.)

  Probability

b.

Compute the probability of a value of 75.0 or less. (Round intermediate

calculations to 2 decimal places. Round final answer to 4 decimal

places.)

  Probability

c.

Compute the probability of a value between 55.0 and 70.0. (Round

intermediate calculations to 2 decimal places. Round final answer

to 4 decimal places.)

  Probability

For the most recent year available, the mean annual cost to attend a private university

in the United States was $26,889. Assume the distribution of annual costs follows the

normal probability distribution and the standard deviation is $4,500.

Ninety-five percent of all students at private universities pay less than what amount?

(Round z value to 2 decimal places and your final answer to the nearest whole

number.)

  Amount

$