What, is there a question or no?
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.
Answer:
Step-by-step explanation:
Given is the probability distribution of a random variable X
X 4 5 6 7 Total
P 0.2 0.4 0.3 0.1 1
x*p 0.8 2 1.8 0.7 5.3
x^2*p 3.2 10 10.8 4.9 28.9
a) E(X) = Mean of X = sum of xp = 5.3

Std dev = square root of variance = 0.9
------------------------------------
b) For sample mean we have
Mean = 5.3
Variance = var(x)/n = 
c) 
Answer:
Step-by-step explanation:
Answer:
D, 344
Step-by-step explanation:
5x6 = 30x2 = 60
6x10 = 60
5x10 = 50x4 = 200
4x6=24 (dont need to divide by two since theres two triangles)
24+60+60+200= 344
Answer:
Ox>5
x is less than 5
means nothing more than 5 but anything less than 5