1- For each of the following, state whether the quantity described is a parameter or a statistic, and give the correct notation.
a). The proportion of all residents in a county who voted in the last presidential election.
b). The mean number of extracurricular activities from a random sample of 50 students at your
school.
c). The difference in proportion who have ever smoked cigarettes, between a sample of 500
people who are 60 years old and a sample of 200 people who are 25 years old.