Math 2000 Solutions 9

Fall 2001

In the News

I can’t comment on all of the different studies that were submitted except to say that it is necessary to analyze a statistical study. For example, a study that reports on the total number of U.S. automobile fatalities during a year or a story about the amount of money that Kevin Costner has made in all of his films are not statistical studies. A statistical study must start with a well-defined population and a then select a random sample from the population.

Unit 5B

6. There could be participation bias in this study. Only those who feel strongly are likely to return the survey; and often, negative opinions provoke more responses. Some people also argued that there could be selection bias because a sample of seniors does not represent the entire student population.

Unit 5C

14a. The companies are qualitative categories; they are not described by numbers and they could be ordered in any way.

14b. A bar graph or possibly a pie chart is most appropriate for these data.

14c. Wal-Mart's sales are three to four times as much as those of any one

of the other retailers listed, all of whom have comparable sales.