Observed and expected

It may be a very silly question, but I have trouble conceptualizing these two terms. I had this contingency table with 2 rows and colums. Is expected value always 50%? I remember otherwise in dice or coin game. Could you kindly explain chi-square (I know you discussed this elsewhere, but) addressing this expected values? Thank you.


TS Contributor
The expected values are the ones we would expect if the two variables are independent*. If the departure from the expectancy is "large enough," the chi-square statistic will be significant.

* Independent means that the probability of one variable occurring or taking on a particular value is not affected by the row or column of the other variable.
So, if there is no association between the two variables in a contingency table, the observed % in a row should be the same as % in a column, am I right??? Not necessarily 50%. I have trouble with understanding why observed % has anything to do with expected %. Thank you.