Microsoft Office Tutorials and References

In Depth Information

**Comparing Results to an Estimate**

returning the probability value, which is what you’re after. But suppose you’ve

manually calculated Chi Square values and want to know the associated

probabilities. Do you have to use a table? Nope — the CHISQ.DIST.RT function comes

to the rescue. And furthermore, if you have a probability and want to know the

associated Chi Square value, you can use the CHISQ.INV.RT function.

Figure 10-3:

Determining

probability.

The RT in the CHISQ.DIST.RT and CHISQ.INV.RT functions is the abbreviation

for Right Tail — the functions in the configuration work with the right tail of

the distribution.

Figure 10-3 demonstrates the CHISQ.DIST.RT and CHI.SQ.INV.RT functions

as well. CHISQ.DIST.RT takes two arguments: a value to be evaluated for a

distribution (the Chi Square value, 1.59 in our example) and the degrees of

freedom (6 in the example). Cell D16 displays 0.953006566, which is the same

probability value returned by the CHISQ.TEST function — just as it should be!

The formula in cell D16 is =CHISQ.DIST.RT(F12,6).

CHISQ.TEST and CHISQ.DIST.RT both return the same probability value but

calculate the result with different arguments. CHISQ.TEST uses the actual

expected and observed values and internally calculates the test statistic to

return the probability. This is done behind the scenes — just the probability

is returned. CHISQ.DIST.RT needs the test statistic fed in as an argument.

To use the CHISQ.DIST.RT function:

1. Position the cursor in the cell where you want the result to appear.

2. Enter
=CHISQ.DIST.RT(
to start the function.

3.ClickthecellthathastheChiSquareteststatistic.