WHICH OF THE FOLLOWING IS THE SLOPE AND Y INTERCEPT?

One number exceeds another by -1. the sum of the numbers is 5. what are the numbers?

maks197457 [2]

X-y=-1
x+y=5
y=x+1
x+x+1=5
2x+1=5
2x=4
x=2
y=x+1
y=2+1
y=3

4 0

3 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

What's the correlation coefficient of this date . 10,11,16,9,7,15,16,10,96,51,62,58,89,81,46,51

dem82 [27]

Assuming the question is in the wrong format and"date" is data.
I chose X= 10,11,16,9,7,15,16,10 and Y= <span>96,51,62,58,89,81,46,51
the correlation cooefficent is -0.3351

</span>

8 0

3 years ago

The vector ~v represents the displacement vector from Portland, Oregon to Houston, Texas. The vector w~ represents the displacem

Art [367]

Answer:

a

the displacement of the plane is $- \= w$

b

The displacement of plane from Portland to Akron with layover at Houston is

$\= v + \= w$

c

the vector which defines this displacement is $\= v + \= w =- 2500 \ km$

Step-by-step explanation:

From the question we are the

The displacement from Portland, Oregon to Houston, Texas. is $\= v$

The displacement from Houston, Texas to Akron, Ohio. is $\= w$ a

a

The motion of the plane in question a is in the opposite direction to vector $\= w$

So the displacement of the plane is $- \= w$

b

The motion of Portland to Houston to Akron is in the direction of both vector $\= v$ and $\= w$ so

The displacement of plane from Portland to Akron with layover at Houston is

$d = \= v + \= w$

c

From the question we are told that the plane flies over Portland to get to Anchorage, Alaska which implies that it is moving in opposite direction to the vector $\= v$

Give that distance from Portland to Houston is $\= v = 3000 km$