Probability Distribution of a Discrete Random Variable

Determine which of the following distribution is NOT a probability distribution. (Remember that a valid probability distribution must add up to 1)

• A

• B

• C

• D

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           0          1          2          3           4           5    
P(X)   0.24    0.37    0.20    0.11    0.05     0.03
What is the probability that a randomly chosen household has at least two cars?

• 0.20

• 0.29

• 0.39

• 0.61

In a certain community, 30% of households have 1 child, 43% have 2 children, and 27% have 3 children. If a household is selected at random, what is the expected number of children in that household? HINT: A Probability table may be helpful.

• 2.00

• 2.13

• 1.97

• 1.27

The table above shows a television station's advertisement sales. The distribution of sales for one 24-hour day is given. Solve for the standard deviation. Round to the nearest hundredth.

• 35.76

• 268.1

• 16.3

• 1279.35

It is the mathematical function that gives the probabilities of occurrence of different possible outcomes for an experiment.

The following table represents the probability distribution X, the employment status of adults in a city.

What is the probability that the adults isn't retired?

Supposed two coins are tossed consecutively and we are interested in the number of heads that will come out. Determine the values of the random variable H (number of heads).

• 0,2,3,4

• 0,1,2,3

• 0,1,2

• 0,1,2,3,4

It is a variable whose value is determined by the outcome of a random experiment.

It is a random variable whose set of assumed values that is countable.

If you select one adult at a random from this community, what is the probability that the adults is employed as part -time?