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eimsori [14]
4 years ago
9

Write and simplify the exact expression for the area of the sidewalk.

Mathematics
1 answer:
Nata [24]4 years ago
3 0
Given area of small circle= πr^²= π×9×9= 81π

and area of greater circle= πr^²= π×11×11= 121π

now area of the sidewalk= area of greater circle (-) area of small circle= 121π-81π=40π

40×22/7=125.714m^²
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Is the number 6+1 rational or irrational?
Lilit [14]

Answer:

Rational

Step-by-step explanation:

An irrational number is any number that cannot be turned into a fraction. 7 can be turned into a fraction.

5 0
3 years ago
The union for a particular industry has determined that the standard deviation of the daily wages of its workers is $20. A rando
Sergeeva-Olga [200]

Answer:

The 90% confidence interval for the true mean daily wage of all union workers in the industry is ($118.6, $125.4). The lower limit is $118.6 and the upper limit is $125.4.

Step-by-step explanation:

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\alpha = \frac{1 - 0.9}{2} = 0.05

Now, we have to find z in the Ztable as such z has a pvalue of 1 - \alpha.

That is z with a pvalue of 1 - 0.05 = 0.95, so Z = 1.645.

Now, find the margin of error M as such

M = z\frac{\sigma}{\sqrt{n}}

In which \sigma is the standard deviation of the population and n is the size of the sample.

M = 1.645\frac{20}{\sqrt{90}} = 3.4

The lower end of the interval is the sample mean subtracted by M. So it is 122 - 3.4 = $118.6

The upper end of the interval is the sample mean added to M. So it is 122 + 3.4 = $125.4

The 90% confidence interval for the true mean daily wage of all union workers in the industry is ($118.6, $125.4). The lower limit is $118.6 and the upper limit is $125.4.

4 0
3 years ago
a patio is in the shape of a regular octagon. the sides have length 5m. Calculate the area of the patio
mihalych1998 [28]

here is the solution.

 Round the answer as needed.

7 0
4 years ago
Please answer this correctly
Olenka [21]

Answer:

28 and 7

35

Step-by-step explanation:

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And the little one is 2*7/2 = 7 in²

The total trapezoid therefore has an area of 28+7=35 in²

4 0
4 years ago
Evaluate each function: 1. p(a) = 3a-2; find p(-5) 2. h(t) = 4t+2; find h(-4) 3. f(a) = 3a-4; find f(1) 4. g(x) = 3x+ 1; find g(
frutty [35]
A-2x = 45 explained the theropod waysiver
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