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mylen [45]
3 years ago
11

A surveyor wishes to lay out a square region with each side having length L. However, because of measurement error, he instead l

ays out a rectangle in which the north-south sides both have length X and the east-west sides both have length Y. Suppose that X and Y are independent and that each is uniformly distributed on the interval [L − A, L + A] (where 0 < A < L). What is the expected area of the resulting rectangle?
Mathematics
1 answer:
RoseWind [281]3 years ago
4 0

Step-by-step explanation:

Area, A = Length,x × Breadth,y

A=xy

When x and y are independent, E(xy) = E(x)E(y)

As x and y have the same distribution, U[L-A,L+A], they have the same mean.

We could argue by symmetry that E(x) = L and E(y) + L, also.

We can also reason this from the fact that, if X ~ U[L-A, L+A], f(x) = 1/(2A) from L-A to L+A

Therefore

E(x)= \int\limits {f(x)} \, dx \\\\=\int\limits^{(L+A)}_{(L-A)} {\frac{1}{2A}x } \, dx

=\int\limits^{(L+A)}_{(L-A)} {\frac{1}{2A}x } \, dx \\\\=[\frac{1}{4A}x^2 ]\limits^{(L+A)}_{(L-A)}

=1/(4A)(L+A)2 - 1/(4A)(L-A)2

= 1/(4A)(L2 + 2AL + A2) - 1/(4A)(L2 - 2AL + A2)

=1/(4A)(2AL+2AL)

= 1/(4A)(4AL)

= L

Thus, E(xy) = E(x)E(y) = L×L = L²

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Mandarinka [93]
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      x^2-12x+45
       ___ ________________________
x+1 | x^3-11x^2+33x+45

      - (x^3+x^2)
       _________________________
            -12x^2+33x+45
          - (-12x^2-12x)
          ______________
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         -(45x+45)
___________
0


Since that works, it's either B or D. We just have to figure out when
</span> x^2-12x+45 equals 0, since there are 3 roots and we already found one. Using the quadratic formula, we end up getting (12+-sqrt(144-180))/2=
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8 0
3 years ago
PLEASE ANYONE?: A number is chosen at random from a set of whole number from 1 to 50. Calculate the probability that the chosen
crimeas [40]

Answer:

10

Take 10 and add it 5 times

Step-by-step explanation:

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8 0
1 year ago
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The sum of two numbers is 61. The larger number is 13 more than the smaller number. What are the numbers?
patriot [66]

Answer: 24 and 37

Step-by-step explanation:

Let the numbers be x and y . Also let us pick x as the larger number.

From the first statement :

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From the second statement :

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Solving the resulting linear equations by substitution method, substitute x = y + 13 into equation 1, then

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The swimming pool shown is a right prism with concave hexagonal bases.... pls help
ludmilkaskok [199]

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