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.
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
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.