The box plot shows the number of years during which 16 schools have participated in a marching band competition: A box plot is titled Years of Participation and labeled Years. Number line from 0 to 10 with primary markings and labels at 0, 5, and 10. The box extends from 3 to 7 on the number line. There is a vertical line at 5. The whiskers end at 1 and 10. At least how many schools have participated for 3 to 7 years? (4 points) 3 schools 5 schools 7 schools 8 schools

the answer to the problem is 4                                                  

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

depends on how many days you are talking about

step-by-step explanation: