Excel offers a smorgasbord of number-crunching tools; in fact, it has more than 50 advanced statistical functions that this chapter hasn't even mentioned. Many of these functions will appeal only to those who already understand concepts like standard deviation, theoretical distributions, and dimensionless Pearson product moment correlation coefficients (a subject of keen interest to all six people in the world who currently use such numbers).
But even if you don't understand any of those concepts (and if you're still wondering whether your inner mathematician may yet emerge), Excel offers two advanced statistical functions— FORECAST( ) and TREND( )—that give you a taste of all that awaits the advanced statistician. While both FORECAST( ) and TREND( ) rely on some complex, behind-the-scenes computations, using them is quite easy, even for non-specialists.
The FORECAST( ) and TREND( ) functions predict missing values based on existing data. These "missing" values may represent experimental data you didn't collect, or future sales numbers for dates that haven't occurred yet. Excel examines the data you have so far (the more the better), and uses a mathematical technique known as the method of least squares to generate a trend line. Excel then uses this trend line to generate the other values you've requested.
Both FORECAST( ) and TREND( ) work similarly and produce the same answers. The difference is that FORECAST( ) is designed to calculate a single value. The ...