could anyone explain chi squared tests?

Question

anonymous · Answer

Explain as in explain the equation or how it works?

anonymous · Answer

equation

anonymous · Answer

$$\sum_{i=1}^{k}(O _{i}-E _{i})^{2}/(E _{i})$$ Where K is the number of categories. O sub i is the observed outcomes of i and E sub i is the expected number of outcomes. 

Do you have a software available to you such as StatCrunch?

anonymous · Answer

That equation is your test statistic. It will give you your value to put into the table to determine your P-Value.

anonymous · Answer

no i'm just using excel

anonymous · Answer

Since I don't know the exact commands for Excel, I'll explain that by hand.

You take your observed value for each number/category (i), and subtract the expected value, which is calculated by your number of samples times the probability of i. 

(Observed value of 1 - expected value of 1)^2/(expected value of 1) + (Observed value of 2 - expected value of 2)^2/(expected value of 2) + etc.

anonymous · Answer

thank you