Now, to calculate our chi-squared statistic, we essentially just take, let me just show it to you. And I'll write it, instead of writing chi, I'm going to write a capital X squared. Sometimes someone will write the actual Greek letter chi here. But I'll write the X squared here so that it will be, and let me write it this way. This is our chi-squared statistic. But I'm going to write it with a capital X instead of a chi because this is going to have approximately a chi-squared distribution. I can't assume that it's exactly.