Business Statistics

Chapter 15 | Multiple Regression Analysis 541

FIGURE 15.51

Minitab Calculator dialog box

will appear on the screen (Figure 15.52). Place ‘sqrtbatchsize’ against Target Variable box. Use

Functions box and place SQRT(numexpr) in the Expression box (as shown in Figure 15.52). Place

batchsize in the ‘numexpr’ part of the SQRT(numexpr). Click OK. A new column, ‘sqrtbatchsize’,

will be created by SPSS. The remaining process is the same as for multiple regression using SPSS.

15.13.5 Logarithm Transformation

Logarithm transformation is often used to verify the assumption of constant error variance (ho-

moscedasticity) and to convert a non-linear model ...