Deck 5: Discrete Probability Distributions

Question 1

Determine whether the random variable described is discrete or continuous. The number of 3-point shots made in a basketball game

A) discrete
B) continuous

Answer 1

A

Question 2

Answer 2

B

Question 3

A) Yes
B) No

Answer 3

B

Question 4

A) the probability values are not discrete.
B) a probability is negative.
C) the probability values do not add to 1.
D) values of the variable are negative.

Question 5

A) 0.69
B) 0.74
C) 0.95
D) 0.26

Question 6

A) 0.148
B) 0.852
C) 0.586
D) 0.061

Question 7

A(n) probability distribution consists of the finite number of values
a random variable can assume and the corresponding probabilities of the values.

Question 8

Question 9

A) 0.26
B) 0.07
C) 0.91
D) 0.09

Question 10

A) No
B) Yes

Question 11

A(n) variable is one in which values are determined by chance.

Question 12

Continuous random variables are obtained from data that can be measured rather than
counted.

Question 13

A) 0.26
B) 0.45
C) 0.33
D) 0.25

Question 14

Determine whether the random variable described is discrete or continuous. The number of minutes you must wait in line at the grocery store

A) discrete
B) continuous

Question 15

Determine whether the random variable described is discrete or continuous. The length in seconds of a randomly-selected TV commercial

A) discrete
B) continuous

Question 16

Determine whether the random variable described is discrete or continuous. The total value of a set of coins

A) discrete
B) continuous

Question 17

The sum of the probabilities of all the events in the sample space of a probability
distribution must equal 1.

Question 18

A) the probability values are not increasing.
B) the probability values are not discrete.
C) the values of the variable are negative.
D) the probability values do not add to 1.

Question 19

Discrete variables have values that can be measured.

Question 20

A) Yes
B) No

Question 21

A) 1.17
B) 0.50
C) 1.50
D) 1.68

Question 22

Construct the probability distribution for the number of heads obtained when
tossing four coins. Draw a graph of the distribution.

Question 23

A) 1.60
B) 2.96
C) 2.92
D) 2.56

Question 24

A) 1.53
B) 5.06
C) 6.00
D) 4.00

Question 25

A) 2.1
B) 2.4
C) 2.0
D) 1.5

Question 26

A) 2.1
B) 1.9
C) 2.3
D) 1.5

Question 27

Question 28

A) 1.28
B) 0.25
C) 2.85
D) 3.50

Question 29

A) 99.8
B) 10.5
C) 11.25
D) 10.0

Question 30

A) 0.25
B) 20
C) 1
D) 4.94

Question 31

A) 0
B) 0.409
C) 0.122
D) 0.287

Question 32

de

A) 1.46
B) 1.89
C) 1.18
D) 2.25

Question 33

A) 1.31
B) 1.83
C) 1.25
D) 1.71

Question 34

A) 3.9
B) 2.6
C) 4.7
D) 5.4

Question 35

bjects

Question 36

A) 1.45
B) 0.92
C) 1.33
D) 0.84

Question 37

A) 1.38
B) 1.32
C) 0.77
D) 0.60

Question 38

de

A) 1.37
B) 2.15
C) 1.18
D) 1.89

Question 39

Question 40

A) 10.75
B) 9.8
C) 95.7
D) 16.25

Question 41

A) 0.0002
B) 0.9983
C) 0.0017
D) 0.0095

Question 42

A) 1.67
B) 2.17
C) 3.17
D) 2.67

Question 43

A) 0.0257
B) 0.0002
C) 0.9973
D) 0.0027

Question 44

The formula for the variance of a probability distribution is .

Question 45

Question 46

Determine the indicated probability for a binomial experiment with the given number of trials n and the given success probability p.
N = 11, p = 0.7, P(9)

A) 0.7000
B) 0.0404
C) 0.0005
D) 0.1998

Question 47

The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 45% of adult Australian sheep dogs weigh 65 pounds or more. A sample
Of 11 adult dogs is studied. What is the probability that more than 8 of them weigh 65 lb
Or more?

A) 0.939
B) 0.0022
C) 0.0610
D) 0.0148

Question 48

Compute the probability of X successes. n = 5, X = 4, p = 0.7

A) 0.640
B) 0.800
C) 0.360
D) 0.7

Question 49

An investor is considering a $25,000 investment in a start-up company. She estimates that she has probability 0.05 of a $20,000 loss, probability 0.2 of a $20,000 profit,
Probability 0.15 of a $35,000 profit, and probability 0.6 of breaking even (a profit of $0).
What is the expected value of the profit?

A) $8250
B) $23,250
C) $10,250
D) $11,667

Question 50

The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 40% of adult Australian sheep dogs weigh 65 pounds or more. A sample
Of 18 adult dogs is studied. What is the probability that no more than 3 of them weigh 65
Lb or more?

A) 0.9918
B) 0.0082
C) 0.9672
D) 0.0328

Question 51

A) 0.2095
B) 0.0001
C) 0.1571
D) 0.0873

Question 52

A) 0.8666
B) 0.0112
C) 0.1334
D) 0.0461

Question 53

The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 40% of adult Australian sheep dogs weigh 65 pounds or more. A sample
Of 14 adult dogs is studied. What is the standard deviation of the number of dogs who
Weigh 65 lb or more?

A) 14
B) 1.833
C) 3.36
D) 5.6

Question 54

Construct a probability distribution for the sum shown on the faces when two
dice are rolled. Find the mean, variance, and standard deviation of the
distribution.

Question 55

The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 30% of adult Australian sheep dogs weigh 65 pounds or more. A sample
Of 19 adult dogs is studied. What is the probability that exactly 8 of them weigh 65 lb or
More?

A) 0.0981
B) 0.9923
C) 0.9019
D) 0.0077

Question 56

If a gambler rolls two dice and gets a sum of 10, he wins $10, and if he gets a sum of three, he wins $20. The cost to play the game is $5. What is the expectation of this
Game?

A) -$2.78
B) $3.06
C) -$3.06
D) $2.78

Question 57

A) 0.0112
B) 0.0017
C) 0.0461
D) 0.9539

Question 58

A) 0.5372
B) 0.4628
C) 0.1960
D) 0.7297

Question 59

An investor is considering a $25,000 investment in a start-up company. She estimates that she has probability 0.05 of a $15,000 loss, probability 0.15 of a $20,000 loss,
Probability 0.35 of a $35,000 profit, and probability 0.45 of breaking even (a profit of
$0)) What is the expected value of the profit?

A) $0
B) $16,000
C) $8500
D) $19,750

Question 60

The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 45% of adult Australian sheep dogs weigh 65 pounds or more. A sample
Of 19 adult dogs is studied. What is the mean number of dogs who weigh 65 lb or more?

A) 19
B) 4.7025
C) 8.55
D) 2.1685

Question 61

A) 375
B) 93.75
C) 9.7
D) 125

Question 62

A coin is tossed five times. Find the probability of getting exactly three heads.

A) 0.156
B) 0.313
C) 0.800
D) 0.125

Question 63

A student takes a 18-question, multiple-choice exam with four choices for each question and guesses on each question. Find the probability of guessing exactly 7 out of 18
Correctly.

A) 0.082
B) 0.918
C) 0.250
D) 0.389

Question 64

In a survey, 65% of the voters support a particular referendum. If 20 voters are
chosen at random, find the standard deviation of the number of voters who
support the referendum.

Question 65

In a large bag of marbles, 25% of them are red. A child chooses 4 marbles from this bag. If the child chooses the marbles at random, what is the chance that the child gets exactly
Three red marbles?

A) 0.063
B) 0.141
C) 0.047
D) 0.211

Question 66

It is estimated that 25% of households own a riding lawn mower. A sample of 16 households is studied. What is the probability that exactly 5 of these own a riding lawn
Mower?

A) 0.8198
B) 0.0002
C) 0.9998
D) 0.1802

Question 67

A pet supplier has a stock of parakeets of which 20% are blue parakeets. A pet store orders 3 parakeets from this supplier. If the supplier selects the parakeets at random,
What is the chance that the pet store gets exactly one blue parakeet?

A) 0.128
B) 0.024
C) 0.384
D) 0.096

Question 68

A multiple choice quiz consists of 100 questions, each with 5 possible answers. Find the mean for the number of correct answers, if a student guesses on each question.

A) 5.0
B) 50.0
C) 95.0
D) 20.0

Question 69

A student takes a 5 question multiple choice quiz with 4 choices for each question. If the student guesses at random on each question, what is the probability that the student gets
Exactly 3 questions correct?

A) 0.022
B) 0.176
C) 0.088
D) 0.066

Question 70

A) 100
B) 8.9
C) 80
D) 400

Question 71

It is estimated that 45% of households own a riding lawn mower. A sample of 12 households is studied. What is the mean number of households who own a riding
Mower?

A) 12
B) 1.7234
C) 2.97
D) 5.4

Question 72

A die is rolled 360 times. Find the standard deviation of the number of times a 3 will be rolled.

A) 50
B) 21.3
C) 7.1
D) 5.9

Question 73

e

A) 210
B) 11.7
C) 136.5
D) 390

Question 74

If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices.

A) 0.085
B) 0.218
C) 0.190
D) 0.162

Question 75

It is estimated that 30% of households own a riding lawn mower. A sample of 12 households is studied. What is the probability that no more than 3 of these own a riding
Lawn mower?

A) 0.7472
B) 0.4925
C) 0.5075
D) 0.2528

Question 76

A jewelry supplier has a supply of earrings which are 10% platinum. A store owner orders five sets of earrings from the supplier. If the supplier selects the pairs of earrings
At random, what is the chance that the jewelry store gets exactly two sets of platinum
Pairs?

A) 0.0729
B) 0.0030
C) 0.3645
D) 0.0405

Question 77

A certain large manufacturing facility produces 20,000 parts each week. The manager of the facility estimates that about 1% of the parts they make are defective. What is the
Variance for the number of defective parts made each week?

A) 138
B) 200
C) 198
D) 14.1

Question 78

A coin is tossed 72 times. Find the standard deviation for the number of heads that will be tossed.

A) 6.78
B) 4.24
C) 18
D) 36

Question 79

It is estimated that 30% of households own a riding lawn mower. A sample of 10 households is studied. What is the probability that more than 7 of these own a riding
Lawn mower?

A) 0.0016
B) 0.9894
C) 0.0001
D) 0.0106

Question 80

It is estimated that 30% of households own a riding lawn mower. A sample of 14 households is studied. What is the standard deviation of the number of households who
Own a riding lawn mower?

A) 2.94
B) 1.7146
C) 14
D) 4.2