ch 15 Random Variables

Which of the following random variables is NOT continuous?

• Amount of gasoline in a car.
• Time it takes to commute to work.
• Number of goals scored by a hockey team.
• Lifetime of a AAA battery.

A random variable X has a mean of 5 and a st. dev of 0.40. A random variable Y has a mean of 8 and a st. dev of 0.60. If both are independent, what is the mean of X + Y?

• 13

• 6.5

• 14

• Not here.

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.2

A random variable X has a mean of 5 and a st. dev of 0.40. A random variable Y has a mean of 8 and a st. dev of 0.60. If both are independent, what is the st. dev of X - Y?

• 0.52
• 0.72
• 1.0
• Not here

Tags

CCSS.HSS.CP.A.2

What is the expected number of orders per week?

• 44.50 orders
• 45.23 orders
• 44.61 orders
• Not here

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.2

A marketing survey compiled data on the number of cars in households. If X = the number of cars

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.CP.B.9

The weight of written reports produced in a certain department has a Normal distribution with mean 60 g and standard deviation 12 g. The probability that the next report will weigh less than 45 g is

• .1056
• .3944
• .1042
• .8944

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.ID.A.4

State whether it is Discrete or Continuous;

The speed of a car

• Discrete

• Continuous

State whether it is Discrete or Continuous;

The sum rolled on a pair of dice

• Discrete

• Continuous

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.CP.A.1

CCSS.HSS.MD.A.1