Part IV: Managing and Analyzing Data
relative weighting of the previous data point and the previously predicted data point. You
also can request standard errors and a chart.
FIGURE 33.4
Descriptive statistics output
The exponential smoothing procedure generates formulas that use the damping factor you
specify. Therefore, if the data changes, Excel updates the formulas.
F-test (two-sample test for variance)
An F-test is a commonly used statistical test that enables you to compare two population
variances. Figure 33.5 shows a small data set and F-test output.
The output for this test consists of the means and variances for each of the two samples,
the value of F, the critical value of F, and the significance of F.
Fourier analysis
Fourier analysis performs a “fast Fourier” transformation of a range of data. Using the
Fourier analysis tool, you can transform a range limited to the following sizes: 1, 2, 4, 8,
16, 32, 64, 128, 256, 512, or 1,024 data points. This procedure accepts and generates com-
plex numbers, which are represented as a text string (not numerical values).
