All categories

2 years ago

Mrs. Adam measured the performance times of middle school orchestra 10 points

Mathematics

1 answer:

jenyasd209 [6]2 years ago

4 0

Answer:

Un alambre de acero de 1.5 m se estira 2.0 mm con fuerza F. El diámetro del alambre de acero es 4.0 mm. El módulo de Young del acero es 2.0 x 1011 Nm-2. Determine la fuerza F aplicada sobre el alambre.

Step-by-step explanation:

You might be interested in

Describe how the graph is related to y=x^2

Otrada [13]

I think the answer is b

but I'm not really sure

I hope this helps you out

5 0

3 years ago

A circular rug measures 8 feet across. What is the area of the rug

Ivanshal [37]

Hey there!

The distance across a circle is called the diameter. Half of the diameter is the radius. To find the area of a circle, you take the radius, square it, and then multiply it by pi. Let's do it below.

8²=64

64*3.14=200.96

Therefore, the area of the rug is 200.96 ft².

I hope this helps! Have a great day.

6 0

3 years ago

A circle with radius of 3 cm sits inside a circle with radius of 5 cm. What is the area of the shaded region? Round your final a

DiKsa [7]

Hello!!

So first you need to find the area of the green circle. The formula for finding area for a circle is A = π r2. So the area for the green circle is 28.26 cm. Then you need to find the area of the blue circle. (Using the same formula) which would be 78.5. Then you subtract the value of the green circle to get the value of the shaded region which then your final answer is 50.24 cm. Hope this helped!!

8 0

3 years ago

Read 2 more answers

Find the value of x, please help!!!!

Fudgin [204]

Value of x is 77 degrees

4 0

3 years ago

Read 2 more answers

Nitrates are groundwater contaminants derived from fertilizer, septic tank seepage and other sewage. Nitrate poisoning is partic

o-na [289]

Answer:

a) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.96})^2}=2401$

And rounded up we have that n=2401

b) $n=\frac{0.07(1-0.07)}{(\frac{0.02}{1.96})^2}=625.22$

And rounded up we have that n=626

And we see that if we have previous info about p the sample size varies a lot.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

Part a

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Since we don't have prior information about the population proportion we can use ase estimator $\hat p =0.5$ . And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.96})^2}=2401$

And rounded up we have that n=2401

Part b

For thi case the estimator for p is $\hat p =0.07$

$n=\frac{0.07(1-0.07)}{(\frac{0.02}{1.96})^2}=625.22$

And rounded up we have that n=626

And we see that if we have previous info about p the sample size varies a lot.

4 0

3 years ago