Probability Distribution of a Discrete Random Variable

Classify: The numbers of cheeseburgers a fast-food restaurant serves each day

• Discrete

• Continuous

Which one of the following is a discrete random variable?

• Sam's height

• Sam's weight

• Time Sam's runs the 110 m hurdles

• Amount of Sam's brothers and sisters

Classify: Height of a plant measured each day for 30 days.

• Discrete

• Continuous

Classify: The time it takes for a light bulb to burn out.

• Discrete

• Continuous

Classify: How many miles it takes to use up a tank of gas.

• Discrete

• Continuous

Is this a probability distribution?

• No

• Yes

Is this a probability distribution?

• No
• Yes

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

• μ = 0.4

• μ = 2.5

• μ = 3

• μ = 0.1

• 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

Determine whether the distribution is a probability distribution, if not state why.

The random variable x represents the number of tickets a police officer writes each shift.

• Yes

• No, its all relative to the day

• No, ΣP(x) ≠ 1

• No, P(1) is negative