Review

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

• 85

• 83.2

• 87.1

• 84.4

Tags

CCSS.HSS.MD.A.2

Choose an American household at random. What is the expected number of cars for that household?

• 1.75
• 1.84
• 2.00
• 2.50

Tags

CCSS.HSS.MD.A.2

Probability can only be values between which two numbers?

• 0 to 2

• 0 to 10

• 0 to 5

• 0 to 1

Tags

CCSS.7.SP.C.5

The following table presents a probability distribution for the number of pets each family has in a certain neighborhood. Find the probability that a randomly selected family has 1 or 2 pets.

• 0.2

• 0.4

• 0.1

• 0.5

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.4

• 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

Tags

CCSS.7.SP.C.7B

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

• 85

• 83.2

• 87.1

• 84.4

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

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.4

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Tags

CCSS.HSS.ID.A.4

A data set has a mean of 290 and a standard deviation of 20. Calculate the z-score for 265.

• $z=250.5$

• $z=1.25$

• $z=-1.02$

• $z=-1.25$

Tags

CCSS.HSS.ID.A.4

A data set has a mean of 300 and a standard deviation of 40. What value would have a z-score of  $z=-2$  ?

• 298

• 296

• 220

• 380

Tags

CCSS.HSS.ID.A.4