B.complex/imaginary roots
The answer is
round cake - 82.42 in²
rectangular cake - 114 in²
Round cake:
d = 7 in
r = d/2 = 7 in / 2 = 3.5 in
h = 2 in
The surface are of a cylinder is:
A = 2πr² + 2πrh
The surface are of the round cake (which is actually a cylindrical cake) excluding the bottom is:
A = 2πr² + 2πrh - πr²
A = πr² + 2πrh
A = 3.14 * 3.5² + 2 * 3.14 * 3.5 * 2
= 38.46 + 43.96
= 82.42 in²
Rectangular cake:
w = 6 in
l = 9 in
h = 2 in
The surface are of a rectangle is:
A = 2wl + 2wh + 2lh
The surface are of the rectangular cake excluding the bottom is:
A = 2wl + 2wh + 2lh - wl
A = wl + 2wh + 2lh
A = 6 * 9 + 2 * 6 * 2 + 2 * 9 * 2
= 54 + 24 + 36
= 114 in²
Mean : m = 2.2
Standard deviation: s = 0.3
m - 1 s = 2.2 - 0.3 = 1.9
m + 1 s = 2.2 + 0.3 = 2.5
For the normal distribution the values less than 1 standard deviation away from the mean account for 68.27 % of the set.
Answer: D ) 68 %
X^2 + 10X + 21
(X + 3)(X + 7)
