Advertising (in thousands) Profit (in thousands 150 200 250 325 | 450 500 525 1) Find a cubic model, f (x), for the profit (in thousands), where x is the advertising expenditure, in thousands of dollars. Do not alter the inputs. Round each coefficient to 2 decimal places. State the function. 2) Find the rate of change function, f '(x), including proper units. 3) Using the model, nd the instantaneous rate of change when $10,000 is being invested in advertising each month. 4) Using the table data, find the average rat-e of change when the advertising expenditure increases from $9,000 to $11,000. 5) Using the graph of the model f(x), estimate the xvalues where the tangent line would be horizontal. Paste a capy of the graph here using these instructions: a Graph f(x) and set the viewing window to a good fit. Click the icon at the top right that is a box with an arrow in it. Click the button to Export Image. b. c. d. Click Download PNG. e. Insert the PNG below and adjust the size as needed. 6) Using the graph of the derivative f '(x), locate the x-values where the derivative is equal to 0 (crosses the x-axis). In Desmos, label this graph 900 instead off '(x) to avoid confusing