Since the creation of a social program, the percent of persons 65 years and over with a family income below the poverty level has declined. The percent can be approximated by the function P(t) -30.43 - 5.94Int, where t is the number of years since 1965. Answer parts a. through d. below. a. Find the percent of persons 65 years and over with family income below the poverty level and the rate of change in 1970. The percent of persons 65 years and over with family income below the poverty level in 1970 was |% (Round to two decimal places as needed.) The rate of change of the percent of persons 65 years and over with family income below the poverty level in 1970 was (Round to four decimal places as needed ) b. Find the percent of persons 65 years and over with family income below the poverty level and the rate of change in 1990. The percent of persons 65 years and over with family income below the poverty level in 1990 was |%. (Round to two decimal places as needed.) The rate of change of the percent of persons 65 years and over with family income below the poverty level in 1990 was % (Round to four decimal places as needed.) c. Find the percent of persons 65 years and over with family income below the poverty level and the rate of change in 2010. The percent of persons 65 years and over with family income below the poverty level in 2010 was|% (Round to toni decimal places as needed )