Mean and Standard Deviation from Probability Distribution

What is the standard deviation of the distribution?

• 1010

• 20

• 60

• √20

Your mail-order company advertises that it ships 90% of its orders within three working days. You select an SRS of 100 of the 5000 orders received in the past week for an audit.

What is the standard deviation?

• 0.04

• 0.004

• 0.3

• 0.03

A realtor has been told that 43% of homeowners in a city prefer to have a finished basement. She surveys a group of 300 homeowners randomly chosen from her client list. Describe the sampling distribution model of the proportion of homeowners in this sample who prefer a finished basement.

• mean = 43%; standard deviation = 1.4%

• mean = 57%; standard deviation = 2.9%

• mean = 57%; standard deviation = 1.4%

• mean = 43%; standard deviation = 2.9%

• There is not enough information to describe the distribution.

It is a list, a table, a graph, or a formula of probabilities associated with each of its possible values.

• Bar Chart

• Normal Distribution

• Probability Distribution Function

• Frequency Distribution Table

What is the mean of the probability distribution?

• 0.43`

• 1.66

• 1.26

• 1.64

What do you call a normal distribution with a mean of 0 and a

standard deviation of 1?

• Frequency Distribution

• Probability Distribution

• Standard Normal Distribution

• Cumulative Distribution

The area under the part of normal curve in the standard normal distribution that lies within 2 standard deviations of the mean is

• 68%

• 95%

• 99.7%

• 100%

The average time for a courier to travel from Manila to Pampanga is 200 minutes, and the standard deviation is 10 minutes. What standard score corresponds to a trip that takes 180 minutes?

What is the area of the region in the normal curve between one standard deviation below the mean and three standard deviations above the mean?

Which of the following is NOT a property of a normal curve?

• The total area under it is 1.

• The curve is symmetric about the center.

• It is divided into positive 2 and negative 2 standard deviations

• The mean, median, and mode have the same value and are located at the same point.