Anyone know what a Chi-Square is used for?

[Stojakapimp]

so my mom is doing some data research stuff and asked me if I knew what Chi-Square was used for. I guess it's some statistical thing but I have never taken a statistics class so I have no clue. So does anyone have any clue?

 

[ddjkdg]

A chi squared test is used to test experimental data and see whether it agrees with a hypothesis or not. You take experimental data and come up with value. Then you look at the graph for a chi squared distribution and if your calculated value exceeds a given number, then you can say with a reasonable amount of certainty that the hypothesis models the data.

 

[Orsorum]

Originally posted by: ddjkdg
A chi squared test is used to test experimental data and see whether it agrees with a hypothesis or not. You take experimental data and come up with value. Then you look at the graph for a chi squared distribution and if your calculated value exceeds a given number, then you can say with a reasonable amount of certainty that the hypothesis models the data.

Pretty much. Oh, how I wish I'd kept my stats book.

Crap, nevermind, I did.

 

[Whisper]

Basically, a chi-squared test determines if your data differs significantly from an expected outcome. Because most experiments are designed to determine whether or not your data differs from a hypothesized value, then as mentioned above, chi-squared tests are generally used in supporting a hypothesis.

Getting any more complicated than that hurts my brain. Just has lots to do with normal curves, sums of squares, and all that good stuff.