Question 61527
m=y1-y2)/x1-x2) [use the slope formula]
(1960, 82.3) and (1980, 139.10) 
Let 1960 = 1
Let 1980=22[identify two coordinate points]
(1, 82.3) and (22, 139.10)
m=(139.10-82.3)/22-1)=56.8/21=2.705[plug-in the values and solve for the slope]
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A) Construct a formula for the amount of municipal solid waste generated in the US by finding the equation of the line through these two points.
y=mx+b [use the slope-intercept form of a line]
139.10=(2.705)(22)+b [plug-in the values for one point and the slope.  Solve.]
139.10=59.51x+b
79.59=b
y=2.705x+79.59 [equation of the line]
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B) Use this formula to predict the amount of municipal solid waste generated in the US in millions of tons in the year 2020.
Let 2020=63
y=2.705(63)+79.59 [plug-in the value of x=63 (year 2020) and solve for y]
y=250.01 million tons of waste will be generated in the year 2020!