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2 years ago

PLEASE HELP

Mathematics

1 answer:

Ronch [10]2 years ago

7 0

Answer:

1 and 5

Step-by-step explanation:

The squares have a side length of 10 and 1 square side is the radius of the half-circles. Since there are two half-circles, find the circumference for one full circle:

$C=2\pi r$

Insert the radius:

$r=10\\C=2\pi *10$

Simplify pi:

$C=2*3.14*10$

Simplify multiplication:

$C=6.28*10\\C=62.8$

The circumference of the circles is 62.8. Now find the perimeter of the exposed squares with side length 10. There are 4 exposed sides, which equals one square. Find the perimeter:

$P=10+10+10+10\\P=10+10+20\\P=10+30\\P=40$

Add the perimeter of the circle and the square together:

$P=62.8+40=102.8$

Now see which of the options gives you the perimeter:

1. $40+20\pi =102.8$ ****

2. $unavailable$

3. $120+20\pi =182.8$

4. $300+100\pi =614.2$

5. $10+10+10\pi +10+10+10\pi =102.8$ ****

Finito.

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Answer:

To Find => The value of x. in the equation below

$20 \div 22 = x \div 11$

Step-by-step explanation:

We will cross Multiply the digits

=>20 \div 22 = x \div 20

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3 years ago

In the past, 21% of all homes with a stay-at-home parent, the father is the stay-at-home parent. An independent research firm ha

Afina-wow [57]

Answer:

A sample size of 79 is needed.

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 $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$\pi = 0.21$

The margin of error is:

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

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 $Z = 1.96$ .

What sample size is needed if the research firm's goal is to estimate the current proportion of homes with a stay-at-home parent in which the father is the stay-at-home parent with a margin of error of 0.09?

A sample size of n is needed.

n is found when M = 0.09. So

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

$0.09 = 1.96\sqrt{\frac{0.21*0.79}{n}}$