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Nina [5.8K]
3 years ago
5

Solve the following system. x 2 - y = 3 x - y = -3 The solution set

Mathematics
1 answer:
Tpy6a [65]3 years ago
8 0
Hello : 
<span>x²- y = 3 ...(1)
 x - y = -3 ...(2)
by (2) : y = x+3
subqct in (1) : x²-x-3 = 3
x²-x-6 =0
(x+2)(x-3) = 0
x+2 =0 or x-3 =0
x=-2 or x=3
if x = -2   y = -2+3 = 1
if x=3      y =3+3 = 6
two solutions : ( -2, 1) , (3,6)</span>
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And the sample size would decrease by 160-65=95 subjects

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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Assuming that the deviation is known we can express the margin of error is given by this formula:

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n=(\frac{z_{\alpha/2} \sigma}{ME})^2   (b)

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n=(\frac{1.64(14.7)}{3})^2 =64.57 \approx 65

So the answer for this case would be n=65 rounded up to the nearest integer

And the sample size would decrease by 160-65=95 subjects

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3 years ago
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