32. Appendix B Data Set: Forecast and Actual Temperatures Refer to Data Set 8 in Appendix B.

a. Use the five-day forecast high temperatures and the actual high temperatures. Is there a correlation? Does a linear correlation imply that the five-day forecast temperatures are accurate?

10-2 Correlation 539

b. Use the one-day forecast high temperatures and the actual high temperatures. Is there a correlation? Does a linear correlation imply that the one-day forecast temperatures are accurate?

c. Which would you expect to have a higher correlation with the actual high temperatures:

the five-day forecast high temperatures or the one-day forecast high temperatures?

Are the results from parts

(a) and

(b) what you would expect? If there is a very high correlation between forecast temperatures and actual temperatures, does it follow that the forecast temperatures are accurate?

Identifying Correlation Errors. In Exercises 33–36, describe the error in the stated conclusion.

(See the list of common errors included in this section.)