"Jason Hall" wrote:
I need to forecast a dollar value for the 2 quarters based on the last 6
quarters dollar value.
Example:
FY07Q1 FY07Q2 FY07Q3 FY07Q4 FY08Q1 FY08Q2 FY08Q3 FY08Q4
$2.76 $2.40 $2.07 $2.36 $2.00 $2.17

Before you use any Excel function, it is important first to graph the data
that you have. For example, FORECAST assumes a linear trend. If you graph
your data, I think you will see that is not a likely assumption.

You can graph the data quickly by simply selecting your data and using the
Chart Wizard on the standard toolbar to plot an XY chart.

In fact, if you select a linear trendline and extend it forward 2 units, you
will see the result that FORECAST gives you. You be the judge as to whether
or not the fits your data. (Note that the RSQ value is around 55%. A good
fit would be 85% or higher.)

What I see might be a decaying sinusoidal curve. I don't know of an Excel
function that plots a trendline for such a curve. Alternatively, the data
reflects a "sideways" trend (a flat horizontal line). Caveat: Don't be
fooled by selecting a 5- or 6-degree ploymomial trendline. Of course, that
fits you data exactly due to a mathematical principle. If you extend the
curve forward 2 units, you will see that it's misleading.

Moreover, my comments assume a sequential time series of the data. You have
not said anything one way or another to justify that assumption. Perhaps the
trend to look for year-over-year per quarter. But IMHO, you do not provide
sufficient information to project such a trend.