Randomly chosen people were observed for about 10 seconds in several public places, such as malls and

Question:

Randomly chosen people were observed for about 10 seconds in several public places, such as malls and restaurants, to see whether they smiled during that time. The table shows the results for different age groups.

a. Find the percentage of each age group that were observed smiling, and compare these percentages.
b. Treat this as a single random sample of people, and test whether smiling and age group are associated, using a significance level of 0.05. Comment on the results.