The is answer is definitely D, because he computed the total population of 3,320 in the survey of his targeted people that he specified which was grade school and high school. In order for his computation to work for his market analysis he used the radius of 5m and the 75% he wanted to achieve.
V=1/3πr^2h
d=3.6 in.
r=1.8 in.
V=1/3×π×1.8^2×3
V≈10.1736 cubic inches. As a result, the volume of the funnel is 10.1736 cubic inches. Hope it help!
y=-5/4x +3
The slope(-5/4) is rise over run and negative because the line is sloping down. The y intercept (3) is the point where the line crosses the y axis.