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3 years ago

The number 15 is the geometric mean of 25 and what other number?

Mathematics

1 answer:

kvv77 [185]3 years ago

4 0

Answer:

Step-by-step explanation:

$\text{The geometric mean of two numbers}\ a\ \text{and}\ b:\\\\M=\sqrt{(a)(b)}\\\\\text{We have}\\\\M=15,\ a=25\\\\\text{substitute:}\\\\15=\sqrt{25b}\qquad\text{square of both sides}\\\\15^2=(\sqrt{25b})^2\\\\225=25a\qquad\text{divide both sides by 25}\\\\\dfrac{225}{25}=\dfrac{25b}{25}\\\\9=b\to b=9$

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Write a number in which the value of the 3 is ten times greater than the value of the 3 in 135, 864

Aleonysh [2.5K]

Answer:

345,456

Step-by-step explanation:

The value of 3 in 135,864 is 30,000.

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There are infinitely many numbers that we can write.

Some examples are:

345,456

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3 years ago

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3 years ago

4 The ratio of corresponding dimensions of two similar solids is 3/4. The surface

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4.

The ratio is 3/4 for corresponding dimensions, the ratio of their surface areas is equal to the square of this ratio:

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Cross multiply:

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Divide 9 to both sides:

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$\sf (\dfrac{3}{4})^3=\dfrac{720}{V}$

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$\sf \dfrac{27}{64}=\dfrac{720}{V}$

Cross multiply:

$\sf 27V=46080$

Divide 64 to both sides:

$\sf V\approx 1706.7~m^3$

5.

A globe is a sphere, use the formula for the volume of a sphere:

$\sf V=\dfrac{4}{3}\pi r^3$

The radius is half of the diameter, so the radius here is 40/2 = 20. Plug it in the formula, use 3.14 to approximate for Pi:

$\sf V=\dfrac{4}{3}(3.14)(20)^3$

Simplify the exponent:

$\sf V=\dfrac{4}{3}(3.14)(8000)$

Multiply:

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4 years ago

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The number 15 is the geometric mean of 25 and what other number?​

The number 15 is the geometric mean of 25 and what other number?