9. You have a globe that has a diameter of 22 inches. Find the volume of

A rectangular swimming pool is twice as long as it is wide. A small concrete walkway surrounds the pool. The walkway is a 2 feet

Ksivusya [100]

Answer:

The width and the length of the pool are 12 ft and 24 ft respectively.

Step-by-step explanation:

The length (L) of the rectangular swimming pool is twice its wide (W):

$L_{1} = 2W_{1}$

Also, the area of the walkway of 2 feet wide is 448:

$W_{2} = 2 ft$

$A_{T} = W_{2}*L_{2} = 448 ft^{2}$

Where 1 is for the swimming pool (lower rectangle) and 2 is for the walkway more the pool (bigger rectangle).

The total area is related to the pool area and the walkway area as follows:

$A_{T} = A_{1} + A_{w}$ (1)

The area of the pool is given by:

$A_{1} = L_{1}*W_{1}$

$A_{1} = (2W_{1})*W_{1} = 2W_{1}^{2}$ (2)

And the area of the walkway is:

$A_{w} = 2(L_{2}*2 + W_{1}*2) = 4L_{2} + 4W_{1}$ (3)

Where the length of the bigger rectangle is related to the lower rectangle as follows:

$L_{2} = 4 + L_{1} = 4 + 2W_{1}$ (4)

By entering equations (4), (3), and (2) into equation (1) we have:

$A_{T} = A_{1} + A_{w}$

$A_{T} = 2W_{1}^{2} + 4L_{2} + 4W_{1}$

$448 = 2W_{1}^{2} + 4(4 + 2W_{1}) + 4W_{1}$

$224 = W_{1}^{2} + 8 + 4W_{1} + 2W_{1}$

$224 = W_{1}^{2} + 8 + 6W_{1}$

By solving the above quadratic equation we have:

W₁ = 12 ft

Hence, the width of the pool is 12 feet, and the length is:

$L_{1} = 2W_{1} = 2*12 ft = 24 ft$

Therefore, the width and the length of the pool are 12 ft and 24 ft respectively.

I hope it helps you!

8 0

3 years ago

A United Nations report shows the mean family income for Mexican migrants to the United States is $27,000 per year. A FLOC (Farm

disa [49]

Answer:

We conclude that the mean family income for Mexican migrants to the United States is $27,000 per year and the provided information is consistent with the United Nations report.

Step-by-step explanation:

We are given that a United Nations report shows the mean family income for Mexican migrants to the United States is $27,000 per year.

A FLOC evaluation of 25 Mexican family units reveals a mean to be $30,000 with a sample standard deviation of $10,000.

Let $\mu$ = true mean family income for Mexican migrants.

So, Null Hypothesis, $H_0$ : $\mu$ = $27,000 {means that the mean family income for Mexican migrants to the United States is $27,000 per year}

Alternate Hypothesis, $H_A$ : $\mu$ $\neq$ $27,000 {means that the mean family income for Mexican migrants to the United States is different from $27,000 per year}

The test statistics that would be used here One-sample t test statistics as we don't know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean family income = $30,000

s = sample standard deviation = $10,000

n = sample of Mexican family = 25

So, the test statistics = $\frac{30,000-27,000}{\frac{10,000}{\sqrt{25} } }$ ~ $t_2_4$

= 1.50

The value of t test statistics is 1.50.

Since, in the question we are not given the level of significance so we assume it to be 5%. Now, at 5% significance level the t table gives critical values of -2.064 and 2.064 at 24 degree of freedom for two-tailed test.

Since our test statistic lies within the range of critical values of t, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that the mean family income for Mexican migrants to the United States is $27,000 per year and the provided information is consistent with the United Nations report.

4 0

3 years ago

Consider the line through (-1, -4) and (1, 2). What is the slope (m) of the line?

zloy xaker [14]

Answer:

3

Explanation:

$\bold{\mathrm{Slope}=\frac{y_2-y_1}{x_2-x_1}}$

$\bold{\left(x_1,\:y_1\right)=\left(-1,\:-4\right),\:\left(x_2,\:y_2\right)=\left(1,\:2\right)}$

$\bold{m=\frac{2-\left(-4\right)}{1-\left(-1\right)}}$

Refine

m = 3

5 0

3 years ago

The points (12, 23) and (14, 45) lie on a line. What is the slope of the line?

ozzi

Answer:

slope= 11

Step-by-step explanation:

(12,23) = (x1,y1)

(14,45) = (x2,y2)

Now,

slope(m)= (y2-y1)/(x2-x1)

=(45-23)/(14-12)

=22/2

=11

5 0

3 years ago

Sum of first n terms of an ap sequance is 3n2+5n.what is the sum of its first n+1 terms.find the sum of its first 10 terms.

inessss [21]

Answer:

a) 3n^2 + 11n + 8

b) 350

Step-by-step explanation:

10) 3(10^2)+ 5*10 = 350

n+1) 3(n+1)^2 + 5(n+1)

3(n^2 + 2n + 1) + 5n+5

3n^2 + 6n+3 + 5n + 5

3n^2 + 11n + 8

3 0

3 years ago