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4 years ago

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The area of a wetland drops by 1/4 every 8 years. What percent of its total area disappears after 40 years?

1 answer:

valentina_108 [34]4 years ago

8 0

40÷8=5
5 × 0.25
= 1 1/2 % lost

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Lostsunrise [7]

Answer:

10^5

Step-by-step explanation:

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3 years ago

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A cone and a cylinder have the same height and their bases are congruent circles

Anettt [7]

Answer:

$30cm^3$

Step-by-step explanation:

the volume of a cylinder is given by:

$v_{cylinder}=\pi r^2 h$

and the volume of a cone is given by:

$v_{cone}=\frac{\pi r^2 h}{3}$

since both have the same height and radius, we can solve each equation for $r^2h$ (because this quantity is the same in both figures) and then match the expressions we find:

from the cylinder's volume formula:

$r^2h=\frac{v_{cylinder}}{\pi}$

and from the cone's volume formula:

$r^2h=\frac{3 v_{cone}}{\pi}$

matching the two previous expressions:

$\frac{v_{cylinder}}{\pi} =\frac{3v_{cone}}{\pi}$

we solve for the volume of a cone $v_{cone}$ :

$v_{cone}=\frac{\pi v_{cylinder}}{3\pi} \\\\v_{cone}=\frac{v_{cylinder}}{3}$

substituting the value of the cylinder's volume $v_{cylinder}=90cm^3$

$v_{cone}=\frac{90cm^3}{3} \\\\v_{cone}=30cm^3$

5 0

3 years ago

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The scores of fourth grade students on a mathematics achievement test follow a normal distribution with a mean of 75 and standar

mamaluj [8]

Answer:

The appropriate solution is:

(a) 0.1056

(b) 0

(c) 0.9544

Step-by-step explanation:

The given values are:

Mean,

$\mu = 75$

Standard deviation,

$\sigma = 4$

(a)

⇒ $P(x>80)=1-(x$

$=1-P[\frac{x-\mu}{\sigma}$

$=1-P[\frac{x-\mu}{\sigma}$

$=1-P(z$

By using the table, we get

$=1-0.8944$

$=0.1056$

(b)

According to the question, the values are:

$n$ = 64

$\mu_\bar{x}$ = 75

Now,

⇒ $\sigma_\bar{x}$ = $\frac{\sigma}{\sqrt{n} }$

= $\frac{4}{\sqrt{64} }$

= $\frac{4}{8}$

= $0.5$

⇒ $P(\bar {x} >80 ) = 1 - P(\bar x$

$=1 - P[\frac{(\bar x-\mu_\bar x)}{\sigma \bar x} < \frac{80-75}{0.5} ]$

$=1-P(z$

By using the table, we get

$=1-1$

$=0$

(c)

As we know,

⇒ $\sigma_\bar x$ = $\frac{\sigma}{\sqrt{n} }$

= $\frac{4}{\sqrt{64} }$

= $\frac{4}{8}$

= $0.5$

then,

= $P(74< \bar x$

= $P[\frac{74-75}{0.5} < \frac{\bar x-\mu \bar x}{\sigma \bar x} < \frac{76-75}{0.5} ]$

= $P(-2$

= $P(z$

By using the table, we get

= $0.9772-0.0228$

= $0.9544$

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3 years ago

The amusement park welcomed a total of 1,655 men, 1,775 women, and 684 children to a special event. This event lasted 22 days. T

vovikov84 [41]

Answer:

187

Step-by-step explanation:

1655+1775+684=4114

4114/22=187

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Find the percent of the octagon that is shaded in

ZanzabumX [31]

<h3>Answer: 62.5%</h3>

Explanation:

We have 5 slices shaded out of 8 total. Therefore, we have 5/8 = 0.625 = 62.5% of this figure is shaded.

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3 years ago

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