It is estimated that t days after a virus begins to spread in a town, the percent of the population infected by the virus is approximated by p(t) = 2t2 + t for 0 S t S 7. a. Find the average rate of change of p with respect to t over the interval 1 to 6 days. b. Find and interpret the instantaneous rate of change of p with respect to t at t = 3. a. Which of the following is the correct expression for the average rate of change over the interval 1 to 6 days? P(1)- 53(6) 6 P(6)P(1) 6-1 p(5) 9(1) 6 1 P(1)P(5) 6-1 LVB The average rate of change of p with respect to t over the interval 1 to 6 days is % per day