15 students equally share 7 pizzas.How much pizza does each student get?

The average size of a new house built in a Hays county in 2010 was 1,872 square feet. A random sample of 40 new homes built in H

vlada-n [284]

Answer:

The test statistic is z = 2.7.

The pvalue of the test is 0.0035 < 0.05, which means that this sample provides enough evidence to conclude that the average house size has increased in the Hays County since 2010.

Step-by-step explanation:

The average size of a new house built in a Hays county in 2010 was 1,872 square feet. Evidence that it has increased?

This means that the null hypothesis is:

$H_0: \mu = 1872$

And the alternate hypothesis is:

$H_a: \mu > 1872$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

1872 is tested at the null hypothesis:

This means that $\mu = 1872$

Sample of 40. The average square footage was 2,031 with a standard deviation of 373 square feet.

This means that $n = 40, X = 2031, \sigma = 373$

Value of the test-statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{2031 - 1872}{\frac{373}{\sqrt{40}}}$

$z = 2.7$

Pvalue and decision:

The pvalue of the test is the probability of finding a sample mean above 2031. This is 1 subtracted by the pvalue of z = 2.7.

Looking at the z-table, z = 2.7 has a pvalue of 0.9965

1 - 0.9965 = 0.0035

The pvalue of the test is 0.0035 < 0.05, which means that this sample provides enough evidence to conclude that the average house size has increased in the Hays County since 2010.

7 0

3 years ago

Midpoint of (2,4) and (2, -7)

slega [8]

Step-by-step explanation:

soln:

let,

(x1,y1) =(2,4)

(x2,y2)=2,-7)

Now,

By midpoint formula,

×= x1+x2

2

= 2+2

2

=4

2

=2,,

And,

Y=y1+y2

2

=4-7

2

= -3

2

Hence ,

The mispoint between points (2,4) and (2,-7) is (2,-3 )

2

6 0

2 years ago

I dont quite understand how to do this

Oxana [17]

Answer:

10

Step-by-step explanation:

substitute -3 in for x

f(-3)=(-3)²+1=

9+1=10

(You can ignore the g(x) part - it has nothing to do with this question.)

6 0

3 years ago

Hi i need help please

CaHeK987 [17]

Search how muCh is a gallon and how much is a quart and these will help you find your answer

3 0

4 years ago

How do i write a direct variation given that y varies directly with x x: 15 y: -5

sp2606 [1]

When we say that y varies directly with x, we mean that whatever value x is scaled up by, y will be scaled up by, too. The simplest kind of direct variation is one where y = x for all values of x. If you multiply x by some value, y must be multiplied by that same value.

More generally, though, you'll have something of the form y = kx, where the variable k here is referred to as the constant of proportionality. Another way you can think of k is as the ratio of y to x.

In this problem, you're given a set of values for x and y, and you'll need to use those to find the constant of proportionality before you set up an equation relating x to y. Substituting our general equation y = kx for the given values, we have:

-5 = k(15)

To get k, simply divide both sides by 15 to obtain:

k = -5/15 = -1/3

So, our general equation, for any x, would be y = (-1/3)x

4 0

3 years ago