Question 1073319
Two points on the line are  (13, 35.55) and (36, 73.50).

What is the missing value, (16, v)?



Two choices.  Linear interpolation, or equation of the line containing the two described points.  The solution used here will be equation of the line.


{{{y-35.55=((73.5-35.55)/(36-13))(x-13)}}}, which is in the point-slope form.  Cost here is y.


{{{y-35.55=(37.95/23)(x-13)}}}

{{{y-35=(1.65)(x-13)}}}

{{{y=1.65x-(1.65)*13+35.55}}}

{{{highlight_green(y=1.65x+14.1)}}}



Cost for 16 HCF of water?
x=16.
{{{highlight(y=1.65*16+14.1=highlight(40.5))}}}