Microsoft Office Tutorials and References

In Depth Information

**Performing an Exponential Regression**

Figure 14.19.

Figure 14.19.
When data is growing at an exponential rate, you use

When data is growing at an exponential rate, you use LOGEST

LOGEST tto

perform a regression analysis.

22. Enter the beginning of the formula: =LOGEST(

=LOGEST(. Enter the known_y'sas

A2:A9. Leave the constvalue blank. Spe-

cify TRUE for stats. The formula should be

=LOGEST(B2:B9,A2:A9,,TRUE).

33. Do not press Enter for the formula. Instead, hold down Ctrl+Shift

while pressing Enter to tell Excel to interpret the result as an array

formula and to return a table of values from LOGEST.

44. Add some labels to help interpret the statistics. The labels shown in

columns D and G are examples.

55. To use the results of the regression in a prediction calculation, enter

a different formula than with LINEST. The formula is Intercept ×

Slope^X. In
Figure 14.19
,
to predict population values for a given gen-

eration in cell I2, use =$F$2*$E$2^I2. Alternatively, you can use the

GROWTH function, discussed in the next section.

B2:B9

B2:B9 and the known_x'sas A2:A9