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4 years ago

Can somebody please help me with number 20?!

Mathematics

2 answers:

Firdavs [7]4 years ago

8 0

It is easily b because you have to subtract the demensions and you get 8 squared

anyanavicka [17]4 years ago

8 0

Answer: Choice B, 8 square cm

-----------------------------------------

Explanation:

A1 = shaded area inside larger rectangle
A2 = shaded area inside smaller rectangle
A3 = unshaded overlapping region

A4 = A1+A2 represents the area of the entire 6 by 8 rectangle
A4 = 8*6
A4 = 48

Similarly,
A5 = A2+A3 is the area of the entire 4 by 5 rectangle
A5 = 4*5
A5 = 20

So we know that
A4 = A1+A3 = 48
A5 = A2+A3 = 20

Or in short,
A1+A3 = 48
A2+A3 = 20

Subtract the equations
A1+A3 = 48
A2+A3 = 20
----------
A1-A2 = 28

The total shaded region is 52, which means,
A1+A2 = 52

The new system of equations is
A1-A2 = 28
A1+A2 = 52
which combine to 2A1 = 80 and that solves to A1 = 40

If A1 = 40, then A2 = 12 after using A1+A2 = 52

Then we use A1+A3 = 48 to find that A3 = 8

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Multiply me by 4. Then subtract 29 and you get 23. What is my number?

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Answer:

13 is your number

Step-by-step explanation:

23 = -29 x 4x

add 29 to both sides

52 = 4x

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3 years ago

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A copy machine makes 104 copies in 3 minutes and 15 seconds. how many copies does it make per minute

Gnesinka [82]

Answer:

<h2>32 copies</h2>

Step-by-step explanation:

First convert 3 minutes and 15 seconds into minutes by converting 15 sec to min and add it to 3min

60 sec = 1min

15 sec = 15 / 60 × 1 min

= 0.25min

Add it to 3min

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Hope this helps you.

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3 years ago

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Step-by-step explanation:

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3 years ago

Someone please help me ASAP!!! Worth 11 points

Nina [5.8K]

Answer:

A' = (-3, 0)

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3 years ago

In a sample of nequals16 lichen specimens, the researchers found the mean and standard deviation of the amount of the radioacti

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Answer:

(a) The confidence level desired by the researchers is 95%.

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Step-by-step explanation:

The mean and standard deviation of the amount of the radioactive element, cesium-137 present in a sample of n = 16 lichen specimen are:

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Now it is provided that the researchers want to increase the sample size in order to estimate the mean μ to within 0.001 microcurie per millilitre of its true value, using a 95% confidence interval.

The (1 - α)% confidence interval for population mean (μ) is:

$CI=\bar x \pm z_{\alpha/2}\times \frac{s}{\sqrt{n}}$

(a)

The confidence level is the probability that a particular value of the parameter under study falls within a specific interval of values.

In this case the researches wants to estimate the mean using the 95% confidence interval.

Thus, the confidence level desired by the researchers is 95%.

(b)

In case of statistical analysis, during the computation of a certain statistic, to estimate the value of the parameter under study, certain error occurs which are known as the sampling error.

In case of the estimate of parameter using a confidence interval the sampling error is known as the margin of error.

In this case the margin of error is 0.001 microcurie per millilitre.

(c)

The margin of error is computed using the formula:

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