Answer
(a) $P=0.0292x+1$
(b) $2.752$ atmospheres
Work Step by Step
(a) Given points $(0,1)$ and $(100,3.92)$, assume $P=mx+b$, we have $m=\frac{3.92-1}{100-0}=0.0292$ and $b=1$, thus we have $P=0.0292x+1$
(b) For $x=60\ ft$, we have $P=0.0292(60)+1=2.752$ atmospheres
