Microsoft Office Tutorials and References

In Depth Information

**Considerations When Using Regression Analysis**

Figure 14.12.

Figure 14.12.
These two data sets can be accurately predicted using regres-

These two data sets can be accurately predicted using regres-

sion.

sion.

The chart on the right shows an exponential growth curve. In this chart, the

dotted line shows the regression line plotted using LOGEST. Again, although

the dotted line does not correlate exactly with the actual data points, it is

fairly close.

Here is the problem: Regression always finds a line to fit your data set.

In
Figure 14.13
,
no apparent correlation exists between sales and time. Each

year, the sales fluctuate wildly up or down. If you asked Excel to use re-

gression, it would gladly predict the dotted line shown in the graph. The prob-