Discrete Random Variables

The number of trout in a lake is....

• continuous
• discrete

If you flip two coins (x representing heads)...
P(X=0) 

• 1/2
• 2
• 1/4

find the value of k

• .23
• 1/7
• 1/3
• .44

True or False
The sum of the probabilities can equal more or less than 1

• True
• False

Two marbles are randomly selected without replacement from a bag containing 4 red and 2 blue marbles. Let X represent the number of red marbles selected.
Find P(X=2)

• 16/30
• 2/30
• 12/30
• 18/30

Find k for the following probability distribution:
P(x)=k(x+2)       for x=1,2,3

• 1/3
• 1/12
• 1/4
• 1/5

When a pair of dice is rolled, D represents the sum of the top faces
Find P(D=7)....simplify answers

• 1/6
• 3/12
• 4/24
• 6/32

Your expected return from throwing a 6 is ⅙ x $10.
What is your overall expected result at the end of one game?

• lose $.50
• gain $.50
• lose $5.00
• gain $5.00

A person rolls a normal six-sided die and wins the number of euros shown on the face.
Find the expedted return from one roll of the die

• $1.00
• $2.00
• $2.50
• $3.50

represents in number form the possible outcomes which could occur for some random experiment

• probability
• spike graph
• random variable
• notation