Please help, I don't understand and I need to find an answer (Chi-square Goodness of Fit)

Question

You are conducting a Goodness of Fit hypothesis test for the claim that all 5 categories are equally likely to be selected. Complete the table. Report all answers correct to three decimal places.

Category	Observed Frequency	Expected Frequency
A	12
B	8
C	7
D	22
E	15

*****The fourth column is (obs-exp)^2/exp, it just didn't show up.*****

What is the chi-square test-statistic for this data?

χ2= __________

Answer 1

The observed frequencies add up to 64. Since all five categories are all equally likely to be selected, the expected values in the 3rd column would all be 64/5 = 12.8. Compute the 4th column as (O-E)^2/E, then sum the 4th column to get the chi-square statistic.