Answer
See below.
Work Step by Step
a) According to the line graph the proportion of students who anticipated a starting salary of $40000$ is $14\%$.
b) Plugging in $s=40$ into the formula we get: $p=-0.01(40)^2+0.8(40)+3.7=-16+32+3.7=19.7$
This estimate is quite far off what we got in part a).
