step  To transform the variable sale, from the menus choose:

Transform
  Compute...

step  Type logsale as the Target Variable.

step  Type LN(sale) as the Numeric Expression.

step  Click OK.

The log transformation is a sensible choice because Amount of Last Sale takes only positive values and is right skewed.

step  Recall the Frequencies dialog box.

step  Deselect sale as an analysis variable.

step  Select logsale as an analysis variable.

step  Click OK.