Education Technology

# Knowledge Base

## Solution 12016: Algorithm Used to Compute Chi Squared On the TI-83 Family, TI-84 Plus Family and TI-Nspire™ Handheld in TI-84 Plus Mode.

### How is Chi Squared computed on the TI-83 family, TI-84 Plus family and TI-Nspire handheld in TI-84 Plus mode?

For the TI-83 family, TI-84 Plus family and TI-Nspire handheld in TI-84 Plus mode, the algorithm used for finding c2 (Chi Squared) of a matrix is as follows:

1) First, an expected matrix is computed based on row and column matrix operations on the observed matrix.
2) Next, the residual is computed based on the difference between the observed matrix and expected matrix.
3) Then, the c2 value is computed based on the residual.
4) Next, the degrees of freedom are computed based on the number of rows and columns.
5) Finally, the probability is computed using the c2 distribution function with the c2 value and degrees of freedom previously computed.

To find the c2 (Chi Squared) of a matrix, please see How to Compute Chi Squared Computations

Please see the TI-83 family and TI-84 Plus family guidebooks for additional information.

Please Note: TI-Nspire handheld in TI-84 Plus mode users may refer to the TI-84 Plus family guidebook.