<PRE><B>Question 1188419</B>
price P=(year-1980)x+ some constant
ordered pair (8, 90600) and (14, 107,600)
slope is difference in y 17000/ difference in x 6,
that is $2833.3
point slope formula is y-y1=m(x-x1), m slope and (x1, y1) a point
y-90600=2833.3(x-8)
y=2833.3x+67934
slope is increase in the price per year.
1991 is x=11
so price was in 1991:  2833.33*11+67934=$99,100.67</PRE>