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2 years ago

Please help me its do tomorrow

Mathematics

1 answer:

PolarNik [594]2 years ago

3 0

2x+3 + 3x-4 + 2x+3 + 3x-4 = 78
10x -2 = 78
10x = 80
x=8

deck is 2(8)+3 by 3(8)-4, or 19 by 20

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2 years ago

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The value of X is 27.

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Answer:

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Assuming the X follows a normal distribution

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And the distribution for $\bar X$ is:

$\bar X \sim N(\mu, \frac{160}{\sqrt{n}})$

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And this value agrees with the sample size given.

For the case of the problem we ar einterested on Me= $60, and we need to find the new sample size required to mantain the confidence level at 95%. We know that n is given by this formula:

$n=(\frac{z_{\alpha/2} \sigma}{Me})^2$

And now we can replace the new value of Me and see what we got, like this:

$n=(\frac{1.96*160}{60})^2 =27.32$

And if we round up the answer we see that the value of n to ensure the margin of error required $Me=\pm 60$ $ is n=28.

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2 years ago

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Answer:

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2 years ago