At the last census, 20% of the people in a town were less than 16 years old, 20% were 16-30, 25% were 31-45, 15% were 46-60, and 20% were over 60. To test to see if the age strucutre of the town has changed a random sample of of 200 residents of the town yields the following results:
Age: <16 16-30 31-45 46-60 >60
Observed Frequency 30 31 37 50 52
Test to see if the age structure has changed (using the 5% level of significance).