Hi. i need to solve for the mean absolute deviation. i know how, but end up with the wrong answers. and also, show me the steps how to get the answer. i chose c as a guess because it was as close as i could get. a plenty!
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18. find the mean absolute deviation, rounded to the nearest hundredth, for the given data set: 20, 22, 32, 20, 20, 45, 52, 60

a. 33.875
b. 16.34
c. 13.875
d. 130.75

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

step-by-step explanation:

cats