Exam 1: The Benefits and Risks of Using Statistics

Suppose you want to determine whether taking vitamins every day helps people lose weight.You survey 200 people who had been on a weight loss program for six months, and ask them whether or not they take vitamins every day, and how much weight they lost.Suppose you found that the people who lost the most weight were more likely to have taken vitamins every day.Does this mean vitamins caused the additional weight loss? Explain why or why not.

While you can learn a lot about the world just by observing it, you can learn even more by conducting a carefully controlled experiment involving statistics.Explain why.

Suppose you wanted to find out what percentage of all Americans approve of the job the president is doing and you mailed questionnaires to 2,000 readers of The Wall Street Journal and compiled the results.This is a(n) __________ sample of all American voters.

To conduct a good statistical study, you have to be sure that your __________ is representative and large enough.

Statistics is about collecting information and using it to help you make a decision.Give an example of a decision that could be made using statistics.

Name one way in which the study of statistics is useful for every day life.

Which of the following statements is true?

__________ is a collection of procedures and principles for gaining and analyzing information in order to help people make decisions when faced with uncertainty.

Suppose you participate in an 'instant poll' on an Internet website which asks, "What is your favorite network TV program at 8 pm (Eastern time) on Thursday night?" After answering the question, you look at the results of the entire poll, and find that 6,423 people have responded to it.Should the results of this poll be a good indicator of what the most popular network TV program is on Thursday nights at 8pm (Eastern time)? Explain why or why not.

Explain the difference between the statistical terms 'population' and 'sample'.