Testing Differences between p and π (2 of 4)
The formula for chi square is:
where χ² is the symbol for the chi square, E is an expected cell frequency, and O is an observed cell frequency. The Σ symbol is summation notation and means to sum up the quantity over both cells. Therefore, the formula says that for each cell you
- take the absolute value of the difference
between the expected cell frequency and the observed cell frequency
- subtract
0.5 (the correction for
continuity)
- square the result,
- divide by the
expected frequency,
- and finally, sum up the values across the cells.
For
the present data,
