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3 years ago

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the

Mathematics

1 answer:

dexar [7]3 years ago

5 0

Answer:

Step-by-step explanation:

Given the equation 4n^2 +28n +49, to get the factors of the equation, we need to factorize the equation completely as shown;

= 4n² +28n +49

Using the general formula n = -b±√b²-4ac/2a

from the equation: a = 4, b = 28 and c = 49

n = -b±√b²-4ac/2a

n = -28±√28²-4(4)(49)/2(4)

n = -28±√784-784/8

n = -28±√0/8

n = -28/8

n = -7/2

The factor of the given function is -7/2

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Your state is considering raising the legal age for consumption of alcoholic beverages to 21 years old. How large a sample size

julsineya [31]

Answer:

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{2.58})^2}=16641$

And rounded up we have that n=16641

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".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

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 99% of confidence, our significance level would be given by $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ . And the critical value would be given by:

$z_{\alpha/2}=-2.58, t_{1-\alpha/2}=2.58$

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 $ME =\pm 0.01$ 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)

For this case we can use as estimator for the proportion $\hat p =0.5$ , since we don't have any other previous info. And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{2.58})^2}=16641$

And rounded up we have that n=16641

8 0

3 years ago

Solve the following logarithmic equations.<br> log[(x^2 + 2x − 3)^4] = 0

saw5 [17]

Answer:

The solutions are x = 1.24 and x = -3.24

Step-by-step explanation:

Hi there!

First, let´s write the equation:

log[(x² + 2x -3)⁴] = 0

Apply the logarithm property: log(xᵃ) = a log(x)

4 log[(x² + 2x -3)⁴] = 0

Divide by 4 both sides

log(x² + 2x -3) = 0

if log(x² + 2x -3) = 0, then x² + 2x -3 = 1 because only log 1 = 0

x² + 2x -3 = 1

Subtract 1 at both sides of the equation

x² + 2x -4 = 0

Using the quadratic formula let´s solve this quadratic equation:

a = 1

b = 2

c = -4

x = [-b± √(b² - 4ac)]/2a

x = [-2 + √(4 - 4(-4)·1)]/2 = 1.24

and

x = [-2 - √(4 - 4(-4)·1)]/2 = -3.24

The solutions are x = 1.24 and x = -3.24

Have a nice day!

4 0

3 years ago

What is the period of the cosecant function graphed below?

telo118 [61]

Step-by-step explanation: The cosecant function is graphed in the given figure. we are to find the period of the function.
The period of a function is the distance travelled by the curve of the function in one complete revolution.
We can see that in the given figure, the distance between two consecutive points is given by

Therefore, the period of the cosecant function is
Thus, the correct option is (B) \pi.

4 0

2 years ago

The length of a rectangle is 12 in. and the perimeter is 56 in. find the width of the rectangle

pentagon [3]

The perimeter p of the rectangle with length l and width w is:
p = 2l + 2w
that is, two times its length and two times its width, lets solve for the width w and substitute known data:
<span>p = 2l + 2w
</span>2w = p - 2l
w = (<span>p - 2l</span>)/2
w = (56 - (2*12))/2
w = (56 - 24)/2
w = 32/2
w = 16
therefore the width of the rectangle is 16 in

8 0

3 years ago

Jack and jill painted one-half of Their bedroom in three-fourths of an hour. At this rate, how long would it take them the pain

zzz [600]

Well they painted HALF the room in 3/4 of an hour.

That means that, considering they keep up the same speed, it will take them 3/4 of an hour to do the OTHER half.

This means that it will take them....

1 and 1/2 hours to do their entire room.

5 0

3 years ago

Read 2 more answers