<span>Semicircle area = circle area / 2 = (pi*r^2)/2
16 in is the radius. Let's call the area of this semicircle s.
3.14*16^2=s
</span><span>Trapezoid area = ((base 1 + base 2) / 2) * h
Here, base 1 is 44 and base 2 is 36. The height (h) is 20. Let's call this trapezoid's area t.
(44+36)/2 *20 = t </span> <span>We can remove the area of the semicircle (that created by the windshield wiper) by subtracting it from the area of the trapezoid.
t - s = uncleaned area
[(44+36)/2 * 20] - [3.14 * 16^2] = uncleaned area</span>
The joint relative frequency values are the top-left four squares, or the intersection of 2 variables, divided by the total number in the bottom-right corner, which is 96.
Find the intersection of Camp and Swimming lessons. The number is 42. Divide this number by 96: 42 ÷ 96 = 43.75%
