A chain of shops looks at their weekly profit in 10 stores across the Falkirk area.
It is expected that everyone's weekly profit will be with a range of
£12,000 12500
The following is a list of the weekly profits.
13600
9100
6600
11200
14050
15600
12800
12900
13400
7800
a)
State what percentage of the stores are below the expected
weekly profit.

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

24+x=y

step-by-step explanation: