Chapter 5.1 AP Statistics

• B
• C
• D
• E

• B
• C
• D
• E

What is the inter-quartile range for these data?

• 3

• 4

• 5

• 6

• More females use social networking sites.
• In general, females use the sites more often than males.
• Approximately the same number of males and females were surveyed.
• About 43% of all students surveyed said they used social networking sites on a weekly basis.

• B
• C
• D
• E

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

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.

A marketing survey compiled data on the number of personal computers in households. X = the number of computers in a randomly-selected household. If you were to randomly select households, what is the probability it would take exactly 8 selections to find one with 5 computers?

• Approximately 0

• 0.02

• 0.03

• 0.32

• Approximately 1

Which of the following is a true statement?

• The binomial setting requires that there are only two possible outcomes for each trial, while the geometric setting permits more than two outcomes.

• A geometric random variable takes on integer values from 0 to n.

• If X is a geometric random variable and the probability of success is 0.85, then the probability distribution of X will be skewed left, since 0.85 is closer to 1 than to 0.

• There is a fixed number of trials in a geometric setting, and the number of trials varies in a binomial setting.

• The distribution of every geometric random variable is skewed right

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