Factorise and simplify (x^3+x^2+x+1) ÷ (x+1)<br>PLS YALL FAST

Suppose a 90% confidence interval for the mean salary of college graduates in a town in Mississippi is given by [$38,737, $50,46

JulsSmile [24]

Answer:

a. The point estimate was of $44,600.

b. The sample size was of 16.

Step-by-step explanation:

Confidence interval concepts:

A confidence interval has two bounds, a lower bound and an upper bound.

A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.

The margin of error is the difference between the two bounds, divided by 2.

a. What is the point estimate of the mean salary for all college graduates in this town?

Mean of the bounds, so:

(38737+50463)/2 = 44600.

The point estimate was of $44,600.

b. Determine the sample size used for the analysis.

First we need to find the margin of error, so:

$M = \frac{50463-38737}{2} = 5863$

Relating the margin of error with the sample size:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.64.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

For this problem, we have that $\sigma = 14300, M = 5863$ . So

$M = z\frac{\sigma}{\sqrt{n}}$

$5863 = 1.645\frac{14300}{\sqrt{n}}$

$5863\sqrt{n} = 1.645*14300$

$\sqrt{n} = \frac{1.645*14300}{5863}$

$(\sqrt{n})^2 = (\frac{1.645*14300}{5863})^2$

$n = 16$

The sample size was of 16.

7 0

3 years ago

What is the value of x ?

statuscvo [17]

Here, Sin Ф = P / H
Sin 31 = x / 430
0.515 = x /430
x = 430 * 0.515
x = 221.45

In short, Your Answer would be 221.45

Hope this helps!

8 0

3 years ago

A herd of 62 horses has 3 white and some black horses. What is the ratio of black horses to all horses?

larisa [96]

The ratio I think would be 59:3

4 0

3 years ago

Read 2 more answers

Two cars leave towns 360 kilometers apart at the same time and travel toward each other. One car's rate is 12 kilometers per hou

mixer [17]

Let x = speed of the first car

the second car is 12 km slower so the seconds car speed is x-12

they each drove 2 hours so 1st car = 2x
2nd car = 2(x-12)

they drove 360 km
so you have 2x + 2(x-12) = 360
solve for x

2x+2(x-12) = 360

2x + 2x-24 = 360

4x-24 = 360

4x = 384
x = 384/4
x = 96

1st car drove at 96 km per hour

slower car drove at 96-12 = 84 km per hour

5 0

3 years ago

How to isolate scalars from a matrix

I am Lyosha [343]

The technique of matrix isolation involves condensing the substance to be studied with a large excess of inert gas (usually argon or nitrogen) at low temperature to form a rigid solid (the matrix). The early development of matrix isolation spectroscopy was directed primarily to the study of unstable molecules and free radicals. The ability to stabilise reactive species by trapping them in a rigid cage, thus inhibiting intermolecular interaction, is an important feature of matrix isolation. The low temperatures (typically 4-20K) also prevent the occurrence of any process with an activation energy of more than a few kJ mol-1. Apart from the stabilisation of reactive species, matrix isolation affords a number of advantages over more conventional spectroscopic techniques. The isolation of monomelic solute molecules in an inert environment reduces intermolecular interactions, resulting in a sharpening of the solute absorption compared with other condensed phases. The effect is, of course, particularly dramatic for substances that engage in hydrogen bonding. Although the technique was developed to inhibit intermolecular interactions, it has also proved of great value in studying these interactions in molecular complexes formed in matrices at higher concentrations than those required for true isolation.

3 0

3 years ago

Factorise and simplify (x^3+x^2+x+1) ÷ (x+1)PLS YALL FAST ​

Factorise and simplify (x^3+x^2+x+1) ÷ (x+1)PLS YALL FAST