All categories

3 years ago

Please help with this

Mathematics

1 answer:

Elza [17]3 years ago

8 0

$area \: of \: circle \: a1 = \pi {r}^{2} = \pi \times {21}^{2} = \\ 441\pi sq \: \: .in \\ area \: of \: triangle \: a2 = \frac{1}{2} bh = \frac{1}{2} \times 20 \times 39 \\ = 390 \: sq.in \\ now \: area \: of \: shaded \: region = a1 - a2 \\ = 441\pi - 390 \\ = 995.44 \: sq.in$

You might be interested in

Select the quadratic that has roots x=8 and x=-5 a x^2 + 3x -40

sergiy2304 [10]

If x = 8, then the factor is (x - 8); likewise, if x = -5, then the factor is (x + 5). FOIL those together and get B

4 0

3 years ago

-23.5-9.5r=-5(7.5r+9)

worty [1.4K]

Yes it is equivelant because if u use ditributive property is will give u the same answer

6 0

3 years ago

Use the distributive property to write an expression equivalent to 5×(3+4)

Lubov Fominskaja [6]

The answer is 5x times 7

8 0

3 years ago

Jen is 3 years older than nancy . Let x represent nancy's age. Let y represent jen's age. Create an equation to show nancy's age

Llana [10]

The equation would be x+3=y
nancy's age + three years= Jen's age

5 0

3 years ago

Read 2 more answers

6.Suppose the Gallup Organization wants to estimate the population proportion of those who think there should be a law that woul

drek231 [11]

Answer:

A sample of $n = (\frac{1.96\sqrt{0.3696*0.6304}}{E})^2$ is needed, in which E is the desired margin of error, as a proportion. If we find a decimal value, we round up to the next whole number.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is of:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

In a previous study of 1012 randomly chosen respondents, 374 said that there should be such a law.

This means that $n = 1012, \pi = \frac{374}{1012} = 0.3696$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

How large a sample size is needed to be 95% confident with a margin of error of E?

A sample size of n is needed, and n is found when M = E.

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$E = 1.96\sqrt{\frac{0.3696*0.6304}{n}}$

$E\sqrt{n} = 1.96\sqrt{0.3696*0.6304}$

$\sqrt{n} = \frac{1.96\sqrt{0.3696*0.6304}}{E}$

$(\sqrt{n})^2 = (\frac{1.96\sqrt{0.3696*0.6304}}{E})^2$

$n = (\frac{1.96\sqrt{0.3696*0.6304}}{E})^2$

A sample of $n = (\frac{1.96\sqrt{0.3696*0.6304}}{E})^2$ is needed, in which E is the desired margin of error, as a proportion. If we find a decimal value, we round up to the next whole number.

4 0

3 years ago