8

The following table summarizes the results of an aptitude test given to six clerks to determine the correlation between test scores (x) and sales in the first month (y) in hundreds of dollars.

X 25 42 33 54 29 36
Y 42 72 50 90 45 48

1 Find the correlation coefficient and interpret the results.

2 Calculate the regression line of y on x and predict the sales of a vendor who obtains 47 on the test.


xi yi xi ·yi xi2 yi2
25 42 625 1,764 1,050
42 72 1,764 5,184 3,024
33 50 1,089 2,500 1,650
54 90 2,916 8,100 4,860
29 45 841 2,025 1,305
36 48 1,296 2,304 1,728
209 347 8,531 21,877 13,617

Correlation and Regression Calculations

Correlation and Regression Calculations

Correlation and Regression Calculations

Correlation and Regression Calculations

Correlation and Regression Calculations

Correlation and Regression Solution

Correlation and Regression Solution