## Thinking Mathematically (6th Edition)

(a) The graph assigns anticipated salary on the x-axis and the percentage of college students on the y-axis. From the provided graph, the desired value would be the point on the line curve whose x-coordinate 30. Consider the given graph and locate the point on the curve against the anticipated starting salary. This can be seen below: This shows the percentage of a college student as: $p=22%$ Thus, the percentage of the student is 22%. (b) Consider the equation as follows: $p=-0.01{{s}^{2}}+0.8s+3.7$ Now, substitute the value of $s$as $30 and find the value of$p$. p=-0.01{{s}^{2}}+0.8s+3.7 =-0.01( 30^2+0.8( 30)+3.7 =-9+24+3.7 =18.7% This shows the percentage of students who anticipated a starting salary of$30 thousand. Compare the calculated value with the estimated value from the part (a). It is done by subtracting both values. 22-18.7=3.3 =3.3% This shows that the calculated value of the formula is 3.3% less than the estimated value from the part (a). 