What is the length of AC

How much time has passed to the nearest quarter hour 7:56am-12:22pm

choli [55]

Answer: 4 hours and 24 minutes

Step-by-step explanation:

8 0

2 years ago

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

3/5x=52 is the answer 120 or 130

postnew [5]

The direct answer to your question is: "No".
because in that equation, 'x' is not 120 or130.

Let's find out what 'x' actually is:

<u>3/5 x = 52</u>

Multiply each side by 5 : 3x = 260

Divide each side by 3 : <em> x = 86 and 2/3 </em>

8 0

3 years ago

Eight times what equals 226

PSYCHO15rus [73]

Answer:

28.25

Step-by-step explanation:

just do 226 divided by 8

3 0

3 years ago

Read 2 more answers

Find the measure of the exterior angle.

PtichkaEL [24]

Answer:

1) 128°

2) 126°

3) 108°

<h2>Question one:</h2>

The square in the corner means 90°. If you add the interior angles of any triangle together, you get 180. in this case, x is in exterior angle, so you subtract it from 180 to get the interior angle.

38 + 90 + (180-x) = 180

38 + 90 + 180 - x = 180

38 + 90 + 180 - 180 - x = 0

38 + 90 + 180 - 180 = x

128 = x

<h2>Question two:</h2><h2></h2>

again, adding all the interior angles makes 180°. use this to make the equation.

3x + (5x-6) + 90 = 180

3x + 5x - 6 = 90

8x = 96

x = 12.

x isn't the answer the question wants, however. if you look at the drawing, the angle that's supplementary to 5x-6 is the exterior angle. so,

180 - (5x-6) = the answer

180 - 5x + 6 = the answer

substitute x for 12

180 - 60 + 6 = the answer

126 = x

<h2>Question three</h2>

again, adding all the interior angles together makes 180°.

(a + 10) + 44 + (180-2a) = 180

a + 10 + 44 + 180 - 2a = 180

-a + 234 = 180

234 - 180 = a

54 = a

however, the question is looking for the exterior angle, not a. in this case, the exterior angle is 2a, so just multiply 54 by 2.

x = 108

8 0

3 years ago