Given the probability model in the table below, what is the expected value of the random variable?
  X        50          20        5
P(X)     0.1         0.3      0.6

• 14
• 4.67
• 5
• 7.5

Tags

CCSS.HSS.MD.A.2

A coin is flipped 3 times. If you get tails once you get $5, tails twice you get $15, and tails on all three flips you get $40. What is the expected amount of money you will get?

• $12.50
• $5
• $7.50
• $10

Tags

CCSS.HSS.MD.A.2

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

• 85

• 83.2

• 87.1

• 84.4

Tags

CCSS.HSS.MD.A.2

You roll a standard die. You win $12 if you roll a six, $6 if you roll a one, and $0 if you roll anything else. What is the expected value of a single roll?

• $3

• $18

• $9

• $2

Answer explanation

P(6) x $12 + P(1) x $6 - P(2 or 3 or 4 or 5) x $0

1/6 x $12 + 1/6 x $6 - 4/6 x $0

$2 + $1 = $3

Tags

CCSS.HSS.MD.B.5A

What is the period of a cosine graph with equation y = 2cos(3x)?

• 2π/3

• π/6

• 3

• 3π/2

Tags

CCSS.HSF-IF.C.7E

What is the period of this function?

• 4π
• 2π
• π
• ½

Tags

CCSS.HSF.TF.A.4

Name the function and how many units the graph shifted vertically.

• sine, 3 units up

• cosine, 3 units down

• cosine, 3 units up

• sine, 3 units up

Tags

CCSS.HSF-IF.C.7E

Set up the problem so that you can solve for X.

• sin X = 41/28

• tan X = 41/28

• cos X = 28/41

• sin X = 28/41

Tags

CCSS.HSG.SRT.C.6

Solve for the missing angle

• 50.5 degrees

• 12.7 degrees

• 36.9 degrees

• 72.2 degrees

Tags

CCSS.HSG.SRT.C.8

What is the length of y in this picture?

• 45
• 5√2
• 90
• 5

Tags

CCSS.HSG.SRT.C.8