Probability Distributions and Expected Value

What does this symbol represent?

• sample mean

• population standard deviation

• population mean

• sample mew

Standard Normal Distribution (mean is 0 standard deviation is 1). For a randomly selected subject, find the probability of a score between 1.37 and 2.42.

• 0.078

• 0.785

• 0.223

• 0.023

What is the probability of an adult male being under 62 inches tall?

• 95%

• 17%

• 5%

• 2.5%

Adult men have a mean height of 70 inches, with a standard deviation of 4 inches.

What is the probability of an adult male being over 74 inches tall?

• 50%

• 17%

• 83%

• 33%

What is the probability of an adult male being over 70 inches tall?

• 50%

• 17%

• 83%

• 33%

The table above shows a television station's advertisement sales. The distribution of sales for one 24-hour day is given. Solve for the mean. Round to the nearest hundredth.

• 31.80

• 15.68

• 0.20

• 1.00

Is this a probability distribution?

• No

• Yes

Find the expected value, round to 3 decimal places.

• 0.4

• 0.6

• 0

• 1.1

Given the probability model in the table below, what is the expected value of the random variable?

• 12

• 4.67

• 14

• 7.5

A small store keeps track of the number X of customers that make a purchase during the first hour that the store is open each day. Based on the records, X has the following probability distribution. What is the average number of customers that the owner can expect to make a purchase in the first hour of opening?

• 0.2

• 1.4

• 2.0

• 3.0