27.47 should be the correct answer!
I can't be entirely sure what you want to "do" about the slope,
but here is how to FIND it if you have the line on the graph:
-- You pick two points on the graph line.
-- Find the difference in 'y' between the two points.
-- Find the difference in 'x' between the two points.
-- The slope of the line between the two points is
(the difference in 'y')
divided by
(the difference in 'x') .
-- If the line on the graph is a straight line, then
the slope is the same everywhere on it.
54-6 = 48
48/4 (Alex-twice, Jennifer, Shannon)
48/4= 12
Alex- 12 x 2 = $24
Jennifer- 12 = $12
Shannon- 12+6 (the 6 I subtracted 54-6) = $18
The axis of symmetry is 2 and the vertex is (2, 4).