Class Median Midpoint, x Income, I 19.5 $12,965 An individual's income varies with age. The table shows the median income I of individuals of different age groups within the United States for a certain year. For each age group, let the class midpoint represent the independent variable x. For the class "65 years and older," assume that the class midpoint is 69.5. Age 15-24 years 25-34 years 35-44 years 45-54 years 29.5 $33,132 39.5 $42,637 49.5 $44,692 55-64 years 59.5 $42,478 Complete parts (a) through (e). 65 years and older 69.5 $24,502 (b) Use a graphing utility to find the quadratic function of best fit that models the relation between age and median income. The quadratic function of best fit is y=-42.427 x + 4026.794 x - 49400.81. (Type integers or decimals rounded to three decimal places as needed.) (c) Use the function found in part (b) to determine the age at which an individual can expect to earn the most income. At about 47.5 years of age, the individual can expect to earn the most income. (Do not round until the final answer. Then round to the nearest tenth as needed.) (d) Use the function in part (b) to predict the peak income earned. The predicted peak income is about $ 46,146. (Round to the nearest dollar as needed.) (e) With a graphing utility, graph the quadratic function of best fit on the scatter diagram. Which of the following shows the quadratic function of best fit?