Answer:
The answer is approximately 12.417
Explanation:
We have:
First, we have that the number of people observed is 149 and the number of months is 12. Since we want to prove that birthdays of 149 persons are equally distributed over the 12 months, then the test should result in an expected value given by:
We are not calculating the value of the chi-square test, because what we want is to find out what is the expected value of applying that test to a uniformly distributed sample.