The average annual price of single-family homes in a county between 2007 and 2017 is approximated by the function P(t) = -0.31713+ 6.66717 - 28.4041 + 260 (0 s t s 10) where Pit) is measured in thousands of dollars and t is measured in years, with t = 0 corresponding to 2007. (a) When was the average annual price of single-family homes in the county highest? Round your answer to two decimal places, If necessary. years after 2007 (b) What was the highest average annual price during the period in question? Round your answer to the nearest whole dollar, dollars (c) When was the average annual price of single-family homes in the county lowest? Round your answer to two decimal places, if necessary. years after 2007 (d) What was the lowest average annual price during the period in question? Round your answer to the nearest whole dollar. dollars Complete the following parts. (e) To answer the above questions, we need the critical numbers of (- Soled-w (f) These critical numbers in the interval (0, 10) are as follows. (Round your answer(s) to two decimal places, if necessary. Enter your answers as a comma- separated list. If an answer does not exist, enter DNE.)