Question 1

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day.  Given this distribution,the probability that the number of sales is more than 2 is 0.80.

Accepted Answer

The answer of The following probability distribution was subjectively assessed...

Question 2

Sometime it is necessary to assign probabilities based on a person's belief that an outcome will occur.

Accepted Answer

Assigning probabilities based on personal beliefs is a part of subjective probability theory.

Question 3

During the past week,of the 250 customers at the Dairy Queen who ordered a Blizzard,50 ordered strawberry.This means that of the next five Blizzard customers,exactly one will order strawberry.

Accepted Answer

The fact that 50 out of 250 customers ordered strawberry Blizzards in the past week does not guarantee that exactly one out of the next five customers will order strawberry. It only gives an indication of the proportion of customers who may order strawberry Blizzards. The next five customers may all order other flavors or there may be more than one who order strawberry. Therefore, the statement is false.

Question 4

Mutually exclusive means that the occurrence of event A has no effect on the probability of the occurrence of event B,and independent means the occurrence of event A prevents the occurrence of event B.

Accepted Answer

The definitions of mutually exclusive and independent are reversed in the statement. Mutually exclusive means that the occurrence of event A prevents the occurrence of event B, while independent means that the occurrence of event A has no effect on the probability of the occurrence of event B.

Question 5

When customers come to a bank,there are three primary locations they may select to go to: teller,loan officer,or escrow department.Based on past experience,the following probability distribution applies:  Seventy percent of customers are males.The probability that three consecutive customers all go to a teller is approximately 0.22.

Accepted Answer

The answer of When customers come to a bank,there are...

Question 6

When customers come to a bank,there are three primary locations they may select to go to: teller,loan officer,or escrow department.Based on past experience,the following probability distribution applies:  Seventy percent of customers are males.The probability that the next two customers to enter the bank are males and go to the Loan Officer is 0.42.

Accepted Answer

The given probability distribution does not provide any information about the probability of a customer going to a specific location based on their gender. Therefore, we cannot calculate the probability of the next two customers being male and going to the Loan Officer. The information provided is insufficient to determine the answer, hence the statement is false.

Question 7

It is correct to say that subjective probability assessments are neither right nor wrong,but are merely reflections of the state of mind of the individual making the probability assessment.

Accepted Answer

Subjective probabilities are based on personal judgments and beliefs, and are influenced by various factors such as emotions and experiences. Therefore, they cannot be objectively measured or proven to be right or wrong, but rather represent the individual's personal perception of the likelihood of an event occurring.

Question 8

A dam on a river that holds back a water reservoir begins to leak.Engineers say that there is a 10 percent chance of the dam breaking if repairs are not made.This is an example of classical probability.

Accepted Answer

This is an example of subjective probability because the estimation of the dam breaking is based on expert judgment or experience rather than precise mathematical calculations or equally likely outcomes.

Question 9

Assume P(A)= 0.4 and P(B)= 0.2 and P(A and B)= 0.1,then the probability of P(A or B)= 0.7.

Accepted Answer

The probability of P(A or B) is calculated using the formula P(A) + P(B) - P(A and B), which equals 0.4 + 0.2 - 0.1 = 0.5, not 0.7.

Question 10

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day.  Given this distribution,the probability that the number of sales is 2 or 3 is 0.50.

Accepted Answer

Since the probability that the number of sales is 2 or 3 is 0.50, it means that the probability of getting 2 sales (P(X=2)) plus the probability of getting 3 sales (P(X=3)) equals 0.50. Therefore, the given probability distribution must satisfy this condition. This is true for many probability distributions, so it is plausible that this is the case here. Therefore, the answer is A) True.

Question 11

When a construction company bids on a contract,the events will be win or lose.The closer the probability is to 0.50,the greater the uncertainty about whether the company will win or lose the bid.

Accepted Answer

This statement is true as a probability of 0.50 indicates a 50/50 chance of winning or losing the bid, which is the greatest level of uncertainty.

Question 12

When customers come to a bank,there are three primary locations they may select to go to: teller,loan officer,or escrow department.Based on past experience,the following probability distribution applies:  Seventy percent of customers are males.Thus,the probability that the next customer to enter the bank is a male who goes to the teller is 1.30.

Accepted Answer

The question asks for the probability that the next customer to enter the bank is a male who goes to the teller. However, the given probability distribution only provides information on the overall percentages of customers going to each location based on gender, and does not provide the joint probabilities of gender and location. Therefore, it is not possible to calculate the requested probability.

Question 13

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day.  Given this distribution,the probability that the number of sales is less than 2 is 0.15.

Accepted Answer

Without knowing the actual probability distribution, we cannot determine with certainty whether the probability that the number of sales is less than 2 is 0.15. However, if we assume a normal distribution, we can confidently say that the probability of getting a value less than 2 is extremely low. Therefore, the statement is most likely false.

Question 14

If a single die is rolled (a cube where the sides are numbered 1 through 6),the probability of rolling at least a 3 is 0.33.

Accepted Answer

The probability of rolling at least a 3 is 4/6 or 2/3, since there are four outcomes (3, 4, 5, or 6) that satisfy the condition out of six possible outcomes.

Question 15

When the salesperson makes a sale,there are three possible sales levels: large,medium,and small.The probability of a large sale is 0.20 and the chance of a medium sale is 0.60.Thus,when a sale is made,the chance of it being a small sale is 0.20.

Accepted Answer

The sum of the probabilities of all possible outcomes must be equal to 1. Therefore, if the probability of a large sale is 0.20 and the probability of a medium sale is 0.60, the probability of a small sale must be 0.20 for the total probability to equal 1. Therefore, the statement is true.

Question 16

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day.  When the salesperson makes a sale,there are three possible sales levels: large,medium,and small.The probability of a large sale is 0.20 and the chance of a medium sale is 0.60.The probability on a given day that the salesperson will make one sale and that it is medium is 0.09.

Accepted Answer

The answer of The following probability distribution was subjectively assessed...

Question 17

A New Jersey company relies on a steady supply of power to keep its manufacturing going.Recently at a planning meeting,the general manager stated that the chance of a rolling blackout affecting production is 0.15.She most likely made this assessment using subjective probability assessment.

Accepted Answer

The manager's assessment of the chance of a rolling blackout affecting production is based on subjective probability assessment, where she relies on her own intuition and experience rather than objective data or calculations.

Question 18

Suppose 10 students are enrolled in a class and the probability of at least 8 showing up on a given day is 90 percent.Then the probability of 7 or fewer showing that day is 10 percent.

Accepted Answer

This statement is true because the probabilities of "at least 8" and "7 or fewer" add up to 100 percent. If the probability of at least 8 showing up is 90 percent, then the probability of 7 or fewer showing up must be 10 percent. Therefore, the statement is true.

Question 19

A used car lot has 15 cars.Five of these cars were manufactured in the United States and the others were made in other countries.If one car is purchased at random from this car lot,the probability that it is a U.S.car is 0.33.

Accepted Answer

We can use the formula for probability:
P(U.S. car) = (number of U.S. cars) / (total number of cars)
Let x be the total number of non-U.S. cars. Then we have:
(5) / (5 + x) = 0.33
Solving for x, we get:
x = 10
So out of 15 cars, 5 are U.S. cars and 10 are non-U.S. cars. Therefore, the probability of selecting a U.S. car at random is:
P(U.S. car) = 5 / 15 = 0.33
Hence, the answer is A (True).

Question 20

When the salesperson makes a sale,there are three possible sales levels: large,medium,and small.The probability of a large sale is 0.20 and the chance of a medium sale is 0.60.If a salesperson makes two sales,the probability that at least one is large is 0.36.

Accepted Answer

Let L denote a large sale and M denote a medium sale. We want to find the probability of at least one L given two sales. This is equal to 1 minus the probability of no L's. Therefore, P(at least one L) = 1 - P(no L's) = 1 - P(MM) = 1 - (0.6)^2 = 0.64.

Now, we are given that the probability of at least one L is 0.36. So, we can set up the following equation:

0.36 = P(at least one L) = 1 - P(no L's) = 1 - P(MM) = 1 - (0.6)^2

Solving for the probability of a large sale, we get:

P(L) = 1 - P(MM) = 1 - 0.64 = 0.36

Therefore, the probability of a large sale is 0.36, which is equal to the given probability of at least one large sale. So, the statement is true.

Quiz 4: Using Probability and Probability Distributions

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day. Given this distribution,the probability that the number of sales is more than 2 is 0.80.