Question

question 6 of 10
the number of cases of a new disease can be modeled by the quadratic regression equation y = -2x^2 + 36x + 6, where x represents the year.
which is the best prediction for the number of new cases in year 15?
a. 614
b. 194
c. 328
d. 96

Explanation:

Step1: Substitute x value

Substitute $x = 15$ into $y=-2x^{2}+36x + 6$.
$y=-2\times15^{2}+36\times15 + 6$

Step2: Calculate powers

Calculate $15^{2}=225$. So $y=-2\times225+36\times15 + 6$.

Step3: Do multiplications

$-2\times225=-450$ and $36\times15 = 540$. Then $y=-450+540 + 6$.

Step4: Do additions

$-450+540=90$, and $90 + 6=96$.

Answer:

D. 96