The function notation f(x)=2x-4 means replace the x on the right-hand side with the value in parentheses on the left.
For example, f(y)=2y-4; f(4)=2(4)-4=4; f(1)=2(1)-4=-2 and so on.
The same principle applies to g(x), for example
g(2)=4(2^2)-3=13,
g(x+1)=4(x+1)^2-3=4(x^2+2x+1)-3=4x^2+8x+4-3=4x^2+8x+1
and so on.
(g of f)(x) is another way to write g(f(x)), therefore
g(f(x))
=g(2x-4) [because f(x)=2x-4
=4(2x-4)^2-3
=4(4x^2-16x+16)-3
=16x^2-64x+64-3
=16x^2-64x+61
We will use integration by substitution, as well as the integrals
∫
1
x
d
x
=
ln
|
x
|
+
C
and
∫
1
d
x
=
x
+
C
∫
x
3
x
2
+
1
d
x
=
∫
x
2
x
2
+
1
x
d
x
=
1
2
∫
(
x
2
+
1
)
−
1
x
2
+
1
2
x
d
x
Let
u
=
x
2
+
1
⇒
d
u
=
2
x
d
x
. Then
1
2
∫
(
x
2
+
1
)
−
1
x
2
+
1
2
x
d
x
=
1
2
∫
u
−
1
u
d
u
=
1
2
∫
(
1
−
1
u
)
d
u
=
1
2
(
u
−
ln
|
u
|
)
+
C
=
x
2
+
1
2
−
ln
(
x
2
+
1
)
2
+
C
=
x
2
2
−
ln
(
x
2
+
1
)
2
+
1
2
+
C
=
x
2
−
ln
(
x
2
+
1
)
2
+
C
Final answer
Well you would take 53% then put it over 100 so you should get 53/100
Substitute the value of y in the equation as -1,
(-1)^2-31(-1)-17 = 1+31-17 = 15
The percentile associated with the mean must be high than 50%
