Questions from Statistics Principles

Q: Use the results of Problem 22 in Section 3.1 and

Use the results of Problem 22 in Section 3.1 and Problem 22 in Section 3.2 to compute the z-scores for all the students. Compute the mean and standard deviation of these z-scores.

Q: Use the fraud-detection data from Problem 25 to do the

Use the fraud-detection data from Problem 25 to do the following. (a) Determine the standard deviation and interquartile range of the data. (b) Suppose the month in which the customer used 346 minutes...

Q: Write a paragraph that explains the meaning of percentiles.

Write a paragraph that explains the meaning of percentiles.

Q: Suppose you received the highest score on an exam. Your friend

Suppose you received the highest score on an exam. Your friend scored the second-highest score, yet you both were in the 99th percentile. How can this be?

Q: Morningstar is a mutual fund rating agency. It ranks a fund’s

Morningstar is a mutual fund rating agency. It ranks a fund’s performance by using one to five stars. A one-star mutual fund is in the bottom 10% of its investment class; a five-star mutual fund is at...

Q: When outliers are discovered, should they always be removed from the

When outliers are discovered, should they always be removed from the data set before further analysis?

Q: Suppose a fundraiser holds a raffle for which each person who enters

Suppose a fundraiser holds a raffle for which each person who enters the room receives a ticket numbered 1 to N, where N is the number of people at the fundraiser. The first person to arrive receives...

Q: Mensa is an organization designed for people of high intelligence. One

Mensa is an organization designed for people of high intelligence. One qualifies for Mensa if one’s intelligence is measured at or above the 98th percentile. Explain what this means.

Q: Explain the advantage of using z-scores to compare observations from

Explain the advantage of using z-scores to compare observations from two different data sets.

Q: Explain the circumstances for which the interquartile range is the preferred measure

Explain the circumstances for which the interquartile range is the preferred measure of dispersion. What is an advantage that the standard deviation has over the interquartile range?