Correlations The study of U.S. cities in Exercise found

Chapter 9, Problem 15RE

(choose chapter or problem)

Problem 15RE

Correlations The study of U.S. cities in Exercise found the mean January Temperature (degrees Fahrenheit), Altitude (feet above sea level), and Latitude (degrees north of the equator) for 55 cities. Here’s the correlation matrix:

	Jan.	Temp	Latitude	Altitude
Jan.	Temp	1.000
Latitude	-0.848	1.000
Altitude	-0.369	0.184	1.000

a) Which seems to be more useful in predicting January Temperature—Altitude or Latitude? Explain.

b) If the Temperature were measured in degrees Celsius, what would be the correlation between Temperature and Latitude?

c) If the Temperature were measured in degrees Celsius and the Altitude in meters, what would be the correlation? Explain.

d) What would you predict about the January Temperatures in a city whose Altitude is two standard deviations higher than the average Altitude?

Exercise

US cities Data from 50 large U.S. cities show the mean January Temperature and the Latitude. Describe what you see in the scatterplot.