# Sensitivity Tables

Another way to perform a sensitivity analysis is to generate a
table of sensitivity values. Do this by pointing to **Sensitivity
Analysis** in the **Tools** menu and clicking **Sensitivity
Table**. Like the **Sensitivity Graph** option, this command
brings up a dialog box where you specify your input and output
nodes.

The result is a table similar to the following:

The first column in a sensitivity analysis table shows the
percentage change on the output that is caused by a 1% change on
the input. In the example above, a 1% change in **Principal**
causes a 1% change in **Payment**, the output node. Similarly,
a 1% change in **Annual Rate** causes a 0.76% change in **Payment**.

The second column in a sensitivity analysis table shows the
absolute amount the output changes for a unit change in an input.
For example, every dollar added to **Principal** causes **Payment**
to go up by 0.73 cents. Every 100% added to **Annual Rate**
adds $10,457 to **Payment**. And, finally, every year added to
**Term** adds $8.83 to **Payment**.

You can use the absolute sensitivity values to create a linear equivalent to your model. The Payment model can be approximated using the equation

*Payment = 1100.65 + 0.0073
Principal + 10457 Annual Rate - 8.8327 Years *

The constant, 1100.65, is the current value of **Payment**
in the original model.

You might have noticed in the sensitivity graph that **Payment**
is not linearly related to **Years**. As **Years**
increases the relative change in **Payment** goes down. The
sensitivity table, however, does not show this effect. The
sensitivity table presents only one value for the relationship
between these two nodes. This value is the sensitivity at the
input node's current value. More specifically, the sensitivity is
calculated as the partial derivative of the output node as a
function of the input node at the input node's current value.