Random Variable Rules

Find the value of c

• 0.8

• 0.2

• 0.3

• 0.1

A discrete random variable X has the probability distributions shown in the table. Find the value of k. (Remember that a valid probability distribution must add up to 1)

• 1/3

• 7/12

• 1/12

• 1/4

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

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

A random variable is defined by a rule that assigns a _______________ to every outcome in a sample space.

• number

• letter

• Event

• probability

Consider the dot plot shown. A trial consists of selecting a single student at random from this sample. Let "x" = the number of candy bars this student sold. Find P(x>2) :

• 4/5

• 3/5

• 2/5

• 2/15

Consider the dot plot shown. A trial consists of selecting a single student at random from this sample. Let "x" = the number of candy bars this student sold.

Find P(x=2) :

• 1/15

• 2/15

• 1/8

• 1/4

Which value of "x" is most likely?

• 6

• 7

• 3

• 3.5