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2 years ago

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:( I Need help! Show work please! Aviva has a total of 52 coins, all of which are either dimes or nickels. The total value of th

e coins is $4.70. Find the number of each type of coin.

1 answer:

Jet001 [13]2 years ago

5 0

Answer:

42 Dimes, 10 Nickels.

Step-by-step explanation:

Dimes are worth $0.10, nickels are worth $0.05.

If D = number of dimes, and N = number of nickels, then the following equations are true:

0.10D + 0.05N = 4.70

D + N = 52

Next, let's multiply the first equation by 10 so that we can subtract the second one from it.

D + 0.50N = 47

(-) D + N = 52

Subtracting the second equation from the first one gives:

-0.5N = -5

-0.5N/-0.5 = -5/-0.5

N = 10

Finally, substitute N in the original second equation to find D.

D + 10 = 52

D + 10 - 10 = 52 - 10

D = 42

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

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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.

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3 years ago

Pls help! (put a joke in ur awnser)

djverab [1.8K]

Answer:

r⁶

Step-by-step explanation:

Cancel the common factors or r⁹ and r³

3 0

2 years ago

Read 2 more answers

A box contains plain pencils and pens. A second box contains color pencils and crayons. One item from each box is chosen at rand

pochemuha

Answer:

1/2

Step-by-step explanation:

its 1 out of 2 chances

6 0

3 years ago

REAL LIFE A cylindrical hazardous waste container has a diameter of 1.5 feet and a height of 1.6 feet. Abo

aivan3 [116]

Answer:

It can hold up to $1.256ft^3$ of waste

<em></em>

Step-by-step explanation:

Given

$D = 1.5ft$ -- Diameter

$h = 1.6ft$ -- height

Required

Determine the amount of waste it can hold

This simply means that we calculate the volume of the cylindrical container.

And this is calculated using:

$Volume = \pi r^2h$

Where

$\pi = 3.14$

and

$r = \frac{D}{2}$

$r = \frac{1.5}{2}$

$r = 0.75$

So, we have:

$Volume = 3.14 * 0.5^2 * 1.6$

$Volume = 1.256ft^3$

<em>Hence, it can hold up to </em> $1.256ft^3$ <em> of waste</em>

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3 years ago

28 in 21 in., 20 in.<br> Is this a right triangle?

ankoles [38]

Answer:

No, it is not a right triangle.

Step-by-step explanation:

The simplest way to determine is testing out the numbers with Pythagorian theorem.

If it complies with the theorem, it is a right triangle.

let's assume c = 28, b = 21, and a = 20

the longest side is the hypotenuse so side c (28 in) will be the hypotenuse.

According to the Pythagorian theorem, the square of the length of hypotenuse must equal to the sum of squares of other two sides.

check:

c^2 = 28^2 = 784

a^2 + b^2 = 21^2 + 20^2 = 841

because c^2 is not equal to a^2 + b^2, the triangle is not a right triangle.

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2 years ago