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###### Math · Calculus
Question details

The cost, in millions of dollars, of building a three-story high school in New York State was estimated to be

C(x) = 2.2 + 0.13x − 0.0001x2   (20 ≤ x ≤ 400)

where x is the number of thousands of square feet. Suppose that you are contemplating building a for-profit three-story high school and estimate that your total revenue will be $0.17 million dollars per thousand square feet. What is the profit function (in millions of dollars)? P(x) = What size school should you build to break even? (Round your answer to three decimal places.) thousand ft2 2, Find a linear equation whose graph is the straight line with the given properties. HINT [See Example 2.] Through (20, −9.2) and increasing at a rate of 7 units of y per unit of x.  y(x) = The following table shows worldwide sales of a certain type of cell phone and their average selling prices in 2012 and 2013. Year 2012 2013 Selling Price ($) 385 315
Sales (millions) 827 1,219

(a) Use the data to obtain a linear demand function for this type of cell phone. (Let p be the price, and let q be the demand).

 q(p) =

3, Use your demand equation to predict sales if the price is lowered to $285. million phones (b) Fill in the blank. For every$1 increase in price, sales of this type of cell phone decrease by  million units.