Answer:
Let X = score of final exam.
X~normal(23, 16)
(a)
percentage of score between 19 and 27
= P(19 < X < 27)
= P((19-23) / sqrt(16) < Z < (27 - 23) / sqrt(16))
= P(-1 < Z < 1)
= 1 - P(Z <= -1) - P(Z >= 1)
= 1 - P(Z >= 1) - P(Z >= 1)
= 1 - 2*P(Z >= 1)
= 1 - 2(0.1587)
= 0.6826
= 68.26%
According to Normal Distribution Table
P(Z>=1) = 1 - P(Z<1) = 1-0.8413
So the final percentage is 68.26%
Answer:

Step-by-step explanation:
The area of a rectangle is equal to
, where
is the length of the rectangle and
is the width of the rectangle. In a rectangle, opposite sides are equal.
Therefore, we can write the following system of equations:

Expand the first equation:

Substitute the second equation into the first (
):

Solving for
:

Answer:
14
Step-by-step explanation:
5x-3+ x+9 + 90= 180
6x+ 96=180
6x=180-96
6x=84
x=84/6
x=14