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Yuri [45]
3 years ago
7

Please teach me on how to answer this question. (addmath question)

Mathematics
1 answer:
arsen [322]3 years ago
5 0

We know that \overline{x}=8 so:

\overline{x}=8\\\\\\\dfrac{\sum\limits_{k=1}^7\,x_k}{7}=8\qquad|\cdot7\\\\\\ \boxed{\sum\limits_{k=1}^7\,x_k=56}

We want to calculate:

\sum\limits_{k=1}^7\,\big(2x_k-3\big)^2=\sum\limits_{k=1}^7\,\big(4x_k^2-12x_k+9\big)=\\\\\\=\sum\limits_{k=1}^7\,4x_k^2-\sum\limits_{k=1}^7\,\big12x_k+\sum\limits_{k=1}^7\,9=4\sum\limits_{k=1}^7\,x_k^2-12\sum\limits_{k=1}^7\,x_k+\sum\limits_{k=1}^7\,9=\\\\\\=4\cdot672-12\cdot56+7\cdot9=2688-672+63=\boxed{2079}

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Circle towns limit form a perfectly circular shape that has a population of 20000 in the population density of 480 people per sq
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Answer:

D =\frac{P}{\pi X^2}

And solving for the radius we got:

X = \sqrt{\frac{P}{\pi D}}

And replacing the data given we got:

X = \sqrt{\frac{480 \frac{people}{km^2}}{\pi *20000 people}}= 0.0874Km

And this value converted to meters is X = 87.40 m

Step-by-step explanation:

For this case we know the population size P = 20000 and we also know the population density D = 480 \frac{people}{km^2}

We can assume that the area is a circle. We also know that the formula for the population density is given by:

D= \frac{P}{A}

Where P represent the number of people and A the area. Since we are assuming a circle then the area is given by:

A = \pi X^2

With X the radius of the circle

And then the populationd density become:

D =\frac{P}{\pi X^2}

And solving for the radius we got:

X = \sqrt{\frac{P}{\pi D}}

And replacing the data given we got:

X = \sqrt{\frac{480 \frac{people}{km^2}}{\pi *20000 people}}= 0.0874Km

And this value converted to meters is X = 87.40 m

6 0
3 years ago
Simplify the expression
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Answer:

Step-by-step explanation:

It might be wrong but i beieve that it is 4 to the 5th multiplied 4 to the 2nd

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What is the conjugate of -3+2i
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3 years ago
Amar wants to make lemonade for a birthday party. He wants to mix 12 tablespoons of sugar in water. He only has a teaspoon which
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Answer:48

Step-by-step explanation:

Given

Amar wants 12 tablespoons of sugar in water.

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i.e. 4\ \text{teaspoon}\equiv 1\ \text{tablespoon}

therefore

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