Answer:
7
Step-by-step explanation:
σ = 4 ; μ =?
8.52 to the left of X
.
P(X < 8.52) = 64.8%
P(X < 8.52) = 0.648
Using the Z relation :
(x - μ) / σ
P(Z < (8.52 - μ) / 4)) = 0.648
The Z value of 0.648 of the lower tail is equal to 0.38 (Z probability calculator)
Z = 8.52 - μ / 4
0.38 = 8.52 - μ / 4
0.38 * 4 = 8.52 - μ
1.52 = 8.52 - μ
μ = 8.52 - 1.52
μ = 7
Answer:
9500
Step-by-step explanation:
If r represents the number of registered voters, we are given that ...
5985 = 0.63·r
r = 5985/0.63 = 9500
9500 people are registered to vote.
Step-by-step explanation:
Area of a trapezium = SOPS/2 × ph
Sops is the sum of 4+10 = <u>1</u><u>4</u>
14/2 is 7. 7×4 = <u>2</u><u>8</u>
<u>A</u><u> </u><u>=</u><u> </u><u>2</u><u>8</u><u>c</u><u>m</u><u>²</u>
Area = L×W
10×6= 60cm²
Answer:
400 m^2.
Step-by-step explanation:
The largest area is obtained where the enclosure is a square.
I think that's the right answer because a square is a special form of a rectangle.
So the square would be 20 * 20 = 400 m^2.
Proof:
Let the sides of the rectangle be x and y m long
The area A = xy.
Also the perimeter 2x + 2y = 80
x + y = 40
y = 40 - x.
So substituting for y in A = xy:-
A = x(40 - x)
A = 40x - x^2
For maximum value of A we find the derivative and equate it to 0:
derivative A' = 40 - 2x = 0
2x = 40
x = 20.
So y = 40 - x
= 40 - 20
=20
x and y are the same value so x = y.
Therefore for maximum area the rectangle is a square.
