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Somebody confirm that I am not a complete moron please and thanks

Ann [662]

Answer:

B

Step-by-step explanation:

Triangle B because 128°>90°

3 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

How do I do it! Answer pls givin the brainliest

pychu [463]

Ok so she has to pay 30 percent more of the 20 dollars she already has to pay because of the tax and then the tip so you multiply 20 by .30 which is six then you add that to 20 which is 26

8 0

3 years ago

Read 2 more answers

The supplement of an angle is 3 times the complement of an angle.

-Dominant- [34]

Let’s says that x is the measure of the angle. X and it’s supplement are equal to 180. X and it’s complement are equal to 90. The supplement is s and the complement is c. S is times c which is the same as 3c.

3c + x = 180

C+x = 90
X = 90 - c

3c + 90 - c = 180
2c = 90
C = 45

The complement of. 45 degree angle is 45 degrees.

The angle is 45 degrees.

6 0

3 years ago

The answer to a,b and c

GuDViN [60]

Answer:

16/45; 4/45; 1125

Step-by-step explanation:

Since you know that 4/9 and 1/5 are used, make them common denominators. So 4/9 would turn into 20/45 and 1/5 would be 9/45. It results in 29/45, but that is the amount spent, so you would subtract 45-29/45, resulting in 16/45. For B, you know that she spent 3/4 of the savings, so you know that 1/4 is not being spent. So use 1/4 multiplied by 16/45 from part A to get 4/45. For C, you know that 4/45 is $100, so I multiplied 45x100 to get 4500 and then divided by 4 to get 4500/4.

8 0

3 years ago