The mean annual precipitation in inches and number of days per year with measurable precipitation by selected cities are given in the following table.What is the R-squared of the regression of the mean annual rainfall as a function of the number of rainy days?
A) 0.28.
B) 0.38.
C) 0.48.
D) 0.58.
E) 0.68.

Question

The mean annual precipitation in inches and number of days per year with measurable precipitation by selected cities are given in the following table.What is the R-squared of the regression of the mean annual rainfall as a function of the number of rainy days? 
A) 0.28. 
B) 0.38. 
C) 0.48. 
D) 0.58. 
E) 0.68.

Quizplus · Accepted Answer

We need to find the R-squared of the regression of the mean annual rainfall as a function of the number of rainy days.
Using Excel or a calculator, we can find the correlation coefficient between the two variables to be 0.62. 
To find the R-squared, we square the correlation coefficient: 
(0.62)^2 = 0.3844 = 0.38 (rounded to two decimal places).
Therefore, the answer is B.

The Mean Annual Precipitation in Inches and Number of Days