A car dealership keeps track of how much it spends on advertising each month and of its monthly revenue. From this information, the list of advertising expenditures and probable associated revenues are shown in the table below. Advertising Revenue (thousands of dollars) (thousands of dollars 3 195 7 215 11 255 13 295 15 335 17 360 18 380 20 395a. Find a cubic polynomial that models the data. Include a single graph of the function and data. You may round to three significant digits. Use descriptive variable names. Do not use y and x. You must use function notation. There are directions in Blackboard on how to find a regression function using excel. You can use your graphing calculator to find the function. Make sure the horizontal axis reflects the data. Round the coefficients to four significant digits. For example, round -0.0674496638 to -0.06745 and round 229.611149 to 229.6. See the video https://learn.desmos.com/regressions to find the cubic regression function. b. Find the first derivative and explain what it means in terms of the data. Use good calculus notation. C. Find the relative extremes and explain what they mean in terms of the problem. Include a sentence on why they do not contribute any significant information. d. Find the second derivative and explain what it means in terms of the data. Use good calculus notation. e. Find the point of diminishing returns and explain what it means in terms of the problem. Be very precise when you write your sentence. Do not write "The point of diminishing returns is (3, 123)"