Answer:
See below
Explanation:
Using the equation (instead of the graph....my answer got deleted for using the graph instead of the equation)
When the ball leaves fingers x = 0 :
a) -1/25 ( 0-10)^2 + 11 = 7 ft
b) max height will be at - b/2a
-1/25 ( x^2 -20x +100 ) + 11 <====expand
-1/25 x^2 + 4/5x +7 a = -1/25 b= 4/5
then - b/2a = - 4/5 / (2* -1/25) = 10=x
sub in this value of x into the equation to find max height = 11ft
c) when x = 15
-1/25 ( 15-10)^2 + 11 = 10 ft