Review One Variable Statistics With Standard Deviation

How many of the students had an ACT composite score of exactly 25?

• Cannot be determined

• 6

• 7

• 9

A marketing survey compiled data on the number of personal computers in households. If X = the number of computers in a randomly-selected household, and we omit the rare cases of more than 5 computers, then X has the given distribution. The standard deviation of X is 1.27. Interpret this value.

• The number of computers in a randomly selected household is within 1.27 of the mean.

• The number of computers in a randomly selected household is exactly 1.27 from the mean.

• The number of computers in a randomly selected household is 1.27, on average.

• The number of computers in a randomly selected household is typically 1.27 from the mean.

• The average number of computers in a randomly selected household is typically 1.27 from the mean.

Let the random variable X represent the profit made on a randomly selected day by a certain store. Assume that X is approximately Normal with mean $360 and standard deviation $50. The least profitable 10% of days have a profit of at most how many dollars?

• $244

• $296

• $370

• $424

• $476

A marketing survey compiled data on the number of personal computers in households. If X = the number of computers in a randomly-selected household, and we omit the rare cases of more than 5 computers, then X has the given distribution. The expected value of X is E(X) =

• 0.40

• 1.00

• 1.45

• 1.66

• 2.50

The number of DVDs rented daily at DVD rental machine has a mean of 134 with a standard deviation of 32. The cost of the electricity to keep the DVD rental machine on is $1.45 per day. Each DVD rental increases the electricity cost by $0.02. What are the mean and standard deviation of the electricity cost per day?

• Mean = $4.13, Standard Deviation = $0.64

• Mean = $4.13, Standard Deviation = $1.77

• Mean = $4.13, Standard Deviation = $2.09

• Mean = $2.68, Standard Deviation = $0.64

• Mean = $2.68, Standard Deviation = $2.09

The number of DVDs rented daily at DVD rental machine has a mean of 134 with a standard deviation of 32. Select two days at random and find the difference in the number of DVDs rented on the two days. What are the mean and standard deviation of the difference in the number of DVDs rented?

• Mean = 0, Standard Deviation = 0

• Mean = 0, Standard Deviation = 64

• Mean = 0, Standard Deviation = 45

• Mean = 92, Standard Deviation = 32

• Mean = 134, Standard Deviation = 32

This data is normally distributed.  What percent of the data is in the shaded region?

• 68%

• 95%

• 99.7%

• 50%

Which car club has the higher median?

• Cruisers

• Car Hops

Which city, Nashville or Dallas, has the lowest Q1?

• Nashville

• Dallas

What is the MODE of this data?

• 90

• 85, 90, and 95

• 85 and 95

• None