Chapter 8 Regression and Correlation 317Table 8-2 Calculating Least-Squares Estimates
Function Description
INTERCEPT(y, x) Calculates the least-squares estimate, a, for known
values y and x.
SLOPE(y, x) Calculates the least-squares estimate, b, for known
values y and x.For example, if the y values are in the cell range A2:A11, and the x val-
ues are in the range B2:B11, then the function INTERCEPT(A2:A11, B2:B11)
will display the value of a, and the function SLOPE(A2:A11, B2:B11) will
display the value of b.EXCEL TIPS
You can also calculate linear regression values using the LINEST
and LOGEST functions, but this is a more advanced topic. Both
of these functions use arrays. You can learn more about these
functions and about array functions in general by using Excel’s
online Help.Exploring Regression
If you wish to explore the concepts behind linear regression, an Explore
workbook has been provided for you.To explore the regression concept:1 Open the Regression workbook in the Explore folder.
2 Review the contents of the workbook. The Explore Regression work-
sheet shown in Figure 8-2 allows you to test the impact of different
intercept and slope estimates on the sum of the squared differences.