For this case, the first thing we should use is the following equation:
c (w) = 0.013w ^ 2-w-7
We note that w = 20 belongs to the interval [5, 30]. Therefore, we can use the equation.
Substituting w = 20 we have:
c (20) = 0.013 * (20) ^ 2- (20) -7
c (20) = - 21.8
Answer:
the wind chill temperature at 0f if the wind speed is 20 miles per hour is:
c (20) = - 21.8
