Answer
See the solution as given below.
Work Step by Step
Equation for slope of a straight line is $y=mx+b$
Here $m=$ slope
a) Refer the given data. we have $b=38.9$
$27.3=m(20)+38.9$
or, $m=-0.58$
Thus, $y=-0.58x+38.9$ ...(1)
b) Refer the given data. we have $b=40$
$24.2=m(20)+40$
or, $m=-0.79$
Thus, $y=-0.79x+40$ ...(2)
c) After solving the equations (1) and (2), we get
$x=5.24, y=35.86$
Thus, (5.24,35.86)=(1990,35.86 %)
