Discrete Probability Distribution

The probability distribution for the random variable x is shown in the table

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• 
• 
• 

Is the distribution below a probability distribution? Why or why not?

• Yes. All P(x) values are between 0 and 1, and ∑P(x) = 1
• No, not all P(x) values are between 0 and 1.
• No, ∑P(x) ≠ 1.

Choose the correct sign

probability of "at least 7"

• P(X>7)

• P(X<7)

• P(X≥7)

• P(X≤7)

Is this a probability distribution?

• No

• Yes

Is this a probability distribution?

• No
• Yes

Eva flips a coin. If she gets heads, she wins $4. If she gets tails, she loses $3. What is her expected value of a coin flip?

• $1

• $0.50

• -$0.50

• $0

Find the mean (expected value) of the probability distribution.

• 85

• 83.2

• 87.1

• 84.4

• Yes, because all of the probabilities are between 0 and 1 inclusive and the sum of all the probabilities is 1.
• No, all probabilities are not be between 0 and 1 inclusive
• No, the sum of all the probabilities is not 1.
• Yes, because the distribution is symmetric

What is the probability distribution of getting a sum of 2?

• 0.0625

• 0.6250

• 0.125

• 0.375

The table represents the probability of guessing correct on a 5 question true-false quiz. Find the mean and the standard deviation.

• μ = .4; σ = 7.5

• μ = 2.5; σ = 1.1

• μ = 3; σ = 1.3

• μ = .1; σ = 0