Fear of darkness

Fear of darkness is a common emotion. The following data were obtained by asking 200 individuals in each age group whether they had serious fears of darkness. At α = 0.01, do we have sufficient evidence to reject the hypothesis that “The same proportion of each age group has serious fears of darkness”?

a. The above table is an incomplete contingency table even though at first glance it might appear to be multinomial. Explain why. (Hint: The contingency table must account for all 1000 people.)

b. Solve using the p-value approach.

c. Solve using the classical approach.