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2 years ago

Need answer to question 19 please !!

Mathematics

1 answer:

grigory [225]2 years ago

4 0

Answer:

(1/3) / (x+1) + (-1/3) / (x+4)

Step-by-step explanation:

1 / (x+1)(x+4) = (A/x+1) + (B/x+4)

1 = ((A/x+1) + (B/x+4)) * (x+1)(x+4)

1 = A*(x+4) + B*(x+1)

* if x = -4

1 = A*(-4+4) + B*(-4+1)

1 = B*(-3)

B = -1/3

** if x = -1

1 = A*(-1+4) + B*(-1+1)

1 = A*(3)

A = 1/3

check: (1/3)/(x+1) + (-1/3)/(x+4) = ((1/3)*(x+4))/((x+1)(x+4)) + ((-1/3)*(x+1))/((x+1)(x+4))

==> ((1/3x + 4/3)+(-1/3x - 1/3)) / ((x+1)(x+4)) = 1 / (x+1)(x+4)

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Marina86 [1]

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Moreover, let CH=y and BC=z

Now, AHC, CHB and ABC are all right triangles. If we write the pythagorean theorem for each of them, we have the following system

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Mice21 [21]

Answer:

We are given:

$\hat{p}=\frac{278}{700}=0.397$

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Therefore, the required sample size is:

$n=\hat{p}(1-\hat{p}) \left(\frac{z_{\frac{0.02}{2}} }{E} \right )^{2}$

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