I have conducted a survey regarding the age range of both customers and non-customers of a particular restaurant. The results can be seen below:
| 25 | 26-40 | 42-65 | 65+ | Total Customers | 17 | 79 | 68 | 10 | 174 Non Customers | 21 | 41 | 65 | 17 | 144
I would like to determine if there is any difference among the two groups regarding age. And in particular which age ranges seem to be significantly different. However, im just confused as to how to come up with expected values.
Glen_b's answer on Can you use the chi-squared test when the expected values are not determined? helped me, however, I'm still confused as to how I would find out if there is a significant difference in an individual age range, as opposed to an overall difference.
If for example, the observed value was 1, and expected 2, would I simply do ((1 - 2) ^2)/2 and use a df of 1?