Question 1

The number of cars arriving at a toll booth in five-minute intervals is Poisson distributed with a mean of 3 cars arriving in five-minute time intervals.The probability of 3 cars arriving over a five-minute interval is _______.

Accepted Answer

A) 0.2700 
B) 0.0498 
C) 0.2240 
D) 0.0001 
E) 0.0020

Question 2

A binomial distribution is better than a Poisson distribution to describe the occurrence of major oil spills in the Gulf of Mexico.

Accepted Answer

A) True 
 B)False

Question 3

The assumption of independent trials in a binomial distribution is not a great concern if the sample size is smaller than 1/20th of the population size.

Accepted Answer

A) True 
 B)False

Question 4

If the owner of a deli wanted to see all the outcomes of how many sandwiches are sold during 2-hour lunch periods with the probabilities of each outcome, this would be __________.

Accepted Answer

A) a discrete random variable 
B) a continuous random variable 
C) the continuous distribution 
D) the normal distribution 
E) a discrete distribution

Question 5

Dorothy Little purchased a mailing list of 2,000 names and addresses for her mail order business, but after scanning the list she doubts the authenticity of the list.She randomly selects five names from the list for validation.If 40% of the names on the list are non-authentic, and x is the number on non-authentic names in her sample, the expected (average)value of x is ______________.

Accepted Answer

A) 2.50 
B) 2.00 
C) 1.50 
D) 1.25 
E) 1.35

Question 6

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system, and orders an inspection of a random sample of vouchers issued since January 1, 2016.A sample of ten vouchers is randomly selected, without replacement, from the population of 2,000 vouchers.Each voucher in the sample is examined for errors and the number of vouchers in the sample with errors is denoted by x.If 20% of the population of vouchers contain errors, P(x>0)is _______________.

Accepted Answer

A) 0.8171 
B) 0.1074 
C) 0.8926 
D) 0.3020 
E) 1.0000

Question 7

Aluminum castings are processed in lots of five each.A sample of two castings is randomly selected from each lot for inspection.A particular lot contains one defective casting; and x is the number of defective castings in the sample.P(x=1)is _______.

Accepted Answer

A) 0.2 
B) 0.4 
C) 0.6 
D) 0.8 
E) 1.0

Question 8

A hypergeometric distribution applies to experiments in which the trials represent sampling with replacement.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following conditions is not a condition for the hypergeometric distribution?

Accepted Answer

A) the probability of success is the same on each trial 
B) sampling is done without replacement 
C) there are only two possible outcomes 
D) trials are dependent 
E) n < 5%N

Question 10

If the owner of a deli wanted to see all the outcomes of the time between arrivals at the deli counter during 2-hour lunch periods with the probabilities of each outcome, this would be __________.

Accepted Answer

A) a discrete random variable 
B) a continuous random variable 
C) the continuous distribution 
D) the normal distribution 
E) a discrete distribution

Question 11

Variables which take on values only at certain points over a given interval are called continuous random variables

Accepted Answer

A) True 
 B)False

Question 12

The number of successes in a hypergeometric distribution is unknown

Accepted Answer

A) True 
 B)False

Question 13

As in a binomial distribution, each trial of a hypergeometric distribution results in one of two mutually exclusive outcomes, i.e., either a success or a failure.

Accepted Answer

A) True 
 B)False

Question 14

A Poisson distribution is characterized by one parameter.

Accepted Answer

A) True 
 B)False

Question 15

A market research team compiled the following discrete probability distribution.In this distribution, x represents the number of automobiles owned by a family. $$\begin{array} { | c | c | } 
\hline x & P ( x ) \
\hline 0 & 0.10 \
\hline 1 & 0.10 \
\hline 2 & 0.50 \
\hline 3 & 0.30 \
\hline
\end{array}$$ Which of the following statements is true?

Accepted Answer

A) This distribution is skewed to the right. 
B) This is a binomial distribution. 
C) This is a normal distribution. 
D) This distribution is skewed to the left. 
E) This distribution is bimodal.

Question 16

A student randomly guesses the answers to a five-question true/false test.If there is a 50% chance of guessing correctly on each question, what is the probability that the student misses no questions?

Accepted Answer

A) 0.000 
B) 0.200 
C) 0.500 
D) 0.031 
E) 1.000

Question 17

In a hypergeometric distribution the population, N, is finite and known.

Accepted Answer

A) True 
 B)False

Question 18

From recent polls about customer satisfaction, you know that 85% of the clients of your company are highly satisfied and want to renew their contracts.If you select a random sample of 30 clients, what is the probability that exactly 25 are highly satisfied?

Accepted Answer

A) .184 
B) .186 
C) .188 
D) .190 
E) .192

Question 19

In a binomial distribution, p, the probability of getting a successful outcome on any single trial, increases proportionately with every success.

Accepted Answer

A) True 
 B)False

Question 20

The number of defects per 1,000 feet of extruded plastic pipe is best modeled with the ________________.

Accepted Answer

A) Poisson distribution 
B) Pascal distribution 
C) binomial distribution 
D) hypergeometric distribution 
E) exponential distribution

Exam 5: Discrete Distributions

The number of cars arriving at a toll booth in five-minute intervals is Poisson distributed with a mean of 3 cars arriving in five-minute time intervals.The probability of 3 cars arriving over a five-minute interval is _______.

A binomial distribution is better than a Poisson distribution to describe the occurrence of major oil spills in the Gulf of Mexico.

The assumption of independent trials in a binomial distribution is not a great concern if the sample size is smaller than 1/20^th of the population size.

If the owner of a deli wanted to see all the outcomes of how many sandwiches are sold during 2-hour lunch periods with the probabilities of each outcome, this would be __________.

Aluminum castings are processed in lots of five each.A sample of two castings is randomly selected from each lot for inspection.A particular lot contains one defective casting; and x is the number of defective castings in the sample.P(x=1) is _______.

A hypergeometric distribution applies to experiments in which the trials represent sampling with replacement.

Which of the following conditions is not a condition for the hypergeometric distribution?

If the owner of a deli wanted to see all the outcomes of the time between arrivals at the deli counter during 2-hour lunch periods with the probabilities of each outcome, this would be __________.

Variables which take on values only at certain points over a given interval are called continuous random variables

The number of successes in a hypergeometric distribution is unknown

As in a binomial distribution, each trial of a hypergeometric distribution results in one of two mutually exclusive outcomes, i.e., either a success or a failure.

A Poisson distribution is characterized by one parameter.

A student randomly guesses the answers to a five-question true/false test.If there is a 50% chance of guessing correctly on each question, what is the probability that the student misses no questions?

In a hypergeometric distribution the population, N, is finite and known.

From recent polls about customer satisfaction, you know that 85% of the clients of your company are highly satisfied and want to renew their contracts.If you select a random sample of 30 clients, what is the probability that exactly 25 are highly satisfied?

In a binomial distribution, p, the probability of getting a successful outcome on any single trial, increases proportionately with every success.

The number of defects per 1,000 feet of extruded plastic pipe is best modeled with the ________________.