What is the area help !

Hello i need help on all 3 of these if you could

adell [148]

Answer:oh okay

Step-by-step explanation:

4 0

3 years ago

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

PLEASE SHOW ALL YOUR WORK TO GET BRAINLIEST AWARD

krek1111 [17]

7x+2y=5;13x+14y=-1 Solution : {x,y} = {1,-1} System of Linear Equations entered : [1] 7x + 2y = 5 [2] 13x + 14y = -1 Graphic Representation of the Equations : 2y + 7x = 5 14y + 13x = -1 Solve by Substitution :

// Solve equation [2] for the variable y

[2] 14y = -13x - 1 [2] y = -13x/14 - 1/14

// Plug this in for variable y in equation [1]

[1] 7x + 2•(-13x/14-1/14) = 5 [1] 36x/7 = 36/7 [1] 36x = 36

// Solve equation [1] for the variable x

[1] 36x = 36 [1] x = 1

// By now we know this much :

x = 1 y = -13x/14-1/14

// Use the x value to solve for y

y = -(13/14)(1)-1/14 = -1 Solution : {x,y} = {1,-1} Processing ends successfully

8 0

3 years ago

Can someone help me with this

jolli1 [7]

Answer:

4 sides

Step-by-step explanation:

A lot of math is about pattern matching. Here, you're asked if sides are the same length (one side matches another), if there are right angles (square corners), and if the number of angles or sides is 4.

You might make the observations ...

pink: 2 pairs of parallel sides that are the same length (4 sides). Adjacent sides are different length.

orange: all 4 sides are congruent and at right angles

blue: 2 pairs of parallel sides that are the same length (4 sides). Adjacent sides are different length.

green: 2 pairs of parallel sides that are the same length--4 sides and 4 right angles. Adjacent sides are different length.

__

The only feature in common is "4 sides."

5 0

2 years ago

Plz help the question is so confusing!!

gizmo_the_mogwai [7]

Answer:

-2

Step-by-step explanation:

because the slope is 2, a perpendicular line must be the inverse

the equation for y1 is y=2x+1

y2= -2y+1

5 0

3 years ago

Read 2 more answers