The idea of a large, stable middle class (defined as those with annual household incomes in 2010 between $42,000 and $126,000 for a family of three), is central to America's sense of itself. But the U.S. middle class shrank steadily from 61% of all adults in 1971 (t = 0) to 51% in 2011 (t = 4), where t is measured in decades. Research has shown that this decline was approximately linear.t (a) Find a linear function f(t) giving the percentage of middle-income adults in decade t, where t = 0 corresponds to 1971. f(t) (b) If this trend continues, what will the percentage of middle-income adults be in 2041? % The quantity demanded x for a certain brand of MP3 players is 100 units when the unit price p is set at $100. The quantity demanded is 1100 units when the unit price is $60. Find the demand equation. Sketch its graph. (Sketch the curve as a segment.) 120 Graph Layers