More Discrete Probability Distributions

All of the probabilities in a probability distribution add up to what?

• 0

• 10

• 1

• .5

The table represents the probability of guessing correct on a 5 question true-false quiz. Find the probability all 5 questions correct.

• .03125

• .15625

• .3125

• .1875

What does P(Y<3) mean?

• The probability that the random variable Y is greater than 3.

• The probability that the random variable Y is less than 3.

• The probability that the random variable X is greater than 3.

• The probability that the random variable X is less than 3.

Consider the following distribution where X = number of mice caught in an apartment in a night:

Mice | Probability

0 | 0.12

1 | 0.20

2 | 0.31

3 | 0.14

4 | 0.16

5 | 0.07

Which of the following means "trapping at least one mouse?"

• X<1

• X<1

• X>1

• X>1

Consider the following distribution where X = number of mice caught in an apartment in a night: Mice | Probability 0 | 0.12 1 | 0.20 2 | 0.31 3 | 0.14 4 | 0.16 5 | 0.07 Which of the following means "trapping less than 2 mice?"

• X<2

• X<3

• X>2

• X>2

A marketing survey compiled data on the number of cars in households.  If X = the number of cars in a randomly selected household, and we omit the rare cases of more than 5 cars, then X has the following probability distribution: 

X P(X)

0 0.24

1 0.27

2 0.20

3 0.11

4 0.05

5 0.03

What is the probability that a randomly chosen household has at least two cars?

• 0.20

• 0.29

• 0.39

• 0.61

A marketing survey compiled data on the number of cars in households. If X = the number of cars in a randomly selected household, and we omit the rare cases of more than 5 cars, then X has the following probability distribution: X P(X) 0 0.24 1 0.27 2 0.20 3 0.11 4 0.05 5 0.03 What is the probability that a randomly chosen household has exactly one car?

• 0.61

• 0.29

• 0.39

• 0.27

Which of the following is NOT a condition of the Binomial distribution?

• All trials must be independent.

• Each trial must be classified as a success or a failure.

• All trials are dependent on each other.

• The number of successes in the trials is counted.

An algebra 2 test has 6 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 6 questions, what is the probability that you get exactly 3 questions correct?

• 0.962

• 0.132

• 0.831

• 0.250

Bob is taking a 100 question test. They have a 90 % probability of getting any one question correct. WHICH IS THE CORRECT FORMULA TO FIND OUT THE PROBABILITY that they will answer EXACTLY 70 questions correctly?

• ₁₀₀C₇₀ ( 0.90 )⁷⁰ ( 0.18 )³⁰

• ₁₀₀C₇₀ ( 0.90 )⁶⁰ ( 0.10 )³⁰

• ₁₀₀C₇₀ ( 0.90 )⁷⁰ ( 0.10 )³⁰

• ₉₉C₇₀ ( 0.90 )⁷⁰ ( 0.10 )³⁰