Microsoft Office Tutorials and References

In Depth Information

**Sampling a population of numbers**

For more information, see “Filling cells and creating data series” in Chapter 8, “Worksheet

editing techniques.”

If the step interval takes the series beyond the specified upper value, the output range

includes the upper value because the last interval is truncated. For example, if you specify a

step interval of 4 and the numbers 1 through 10, Excel creates the series 1, 5, 9, and 10.

Sampling a population of numbers

The Sampling tool extracts a subset of numbers from a larger group (or population) of

numbers. From an input range, you can sample a specified number of values at random or

at every
n
th value. The Sampling tool copies the extracted numbers to an output range you

specify. Click the Data Analysis button on the Data tab, select Sampling, and then click OK

to display the Sampling dialog box shown in Figure 17-15.

Figure 17-15
The Sampling tool extracts a random or periodic subset from a numeric

population.

The values in the input range must be numeric. They can include blank values and dates,

provided you type the dates as numbers, not text. For example, to simplify a chart of daily

commodity prices, you can use the Sampling tool to extract every
n
th data point and then

create a new plot from the extracted data.

Note

To perform the equivalent of sampling from a range containing text values, set up a

series of ascending integers beginning at 1 in a column alongside the text values, and

then use the Sampling tool to extract numbers from this series. Then you can assemble

a list of sampled text values by using the resulting numbers as arguments to the INDEX

function. For more information, see “The INDEX function” in Chapter 14.