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3 years ago

Anyone know this? Help pls!

Mathematics

1 answer:

cluponka [151]3 years ago

4 0

Answer:

Step-by-step explanation:

r = 4.9 miles

Area of circle = πr²

= 3.14 * 4.9 * 4.9

= 75.39 square miles

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Use any method to solve the equation. If necessary, round to the nearest hundredth. PLEASE HELP SOON!!!

masha68 [24]

We have that
x² + x − 30 = 0

using a graph tool
see the attached figure

the solution is
x=-6
x=5

the answer is the option
b. 5, –6

8 0

3 years ago

According to a Gallup poll of 1012 people, about one-third of (32%) of Americans keep a dog for protection. Find the:Margin of E

WINSTONCH [101]

The margin of error of the proportion given is of 2.9%.
Applying the margin of error, the confidence interval is (29.1%, 34.9%).

-----------------------

The margin of error of a confidence interval of a proportion $\pi$ in a sample of size n, with a confidence level of $1-\alpha$ , is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

The confidence interval is:

$\pi \pm M$

In this problem:

Poll of 1012 people, thus $n = 1012$ .
32% keep a dog, thus $\pi = 0.32$

95% confidence level

Thus $\alpha = 0.05$ , z is the z-score that has a p-value of $1 - \frac{0.05}{2} = 0.975$ , so $z = 1.96$ .

The margin of error is:

$M = 1.96\sqrt{\frac{0.32(0.68)}{1012}} = 0.029$

As a percent, 2.9%, as 0.029 x 100% = 2.9%.

Now for the confidence interval, which is percentage plus/minus margin of error, thus:

$32 - 2.9 = 29.1$

$32 + 2.9 = 34.9$

The confidence interval is (29.1%, 34.9%).

A similar problem is given at brainly.com/question/16807970

4 0

3 years ago

) Set up a double integral for calculating the flux of F=3xi+yj+zk through the part of the surface z=−5x−2y+2 above the triangle

Fynjy0 [20]

The surface (call it $S$ ) is a triangle with vertices at the points

$x=0,y=0\implies z=2\implies(0,0,2)$

$x=0,y=2\implies z=-2\implies(0,2,-2)$

$x=2,y=0\implies z=-8\implies(2,0,-8)$

Parameterize $S$ by

$\vec s(u,v)=(1-v)(2,0,-8)+v\bigg((1-u)(0,2,-2)+u(0,0,2)\bigg)=(2-2v,2v-2uv,-8+6v+4uv)$

with $0\le u\le1$ and $0\le v\le1$ . Take the normal vector to $S$ to be

$\vec s_v\times\vec s_u=(20v,8v,4v)$

Then the flux of $\vec F$ across $S$ is

$\displaystyle\iint_S\vec F(x,y,z)\cdot\mathrm d\vec S=\int_0^1\int_0^1\vec F(x(u,v),y(u,v),z(u,v))\cdot(\vec s_v\times\vec s_u)\,\mathrm du\,\mathrm dv$

$=\displaystyle\int_0^1\int_0^1(6-6v,2v-2uv,-8+6v+4uv)\cdot(20v,8v,4v)\,\mathrm du\,\mathrm dv$

$=\displaystyle8\int_0^1\int_0^1(11v-10v^2)\,\mathrm du\,\mathrm dv=\boxed{\frac{52}3}$

8 0

4 years ago

3x+2=5x What is the answer for this solving equations with variables on each side

Yanka [14]

3x +2= 5x
-3x
2= 2x
/2
1= x
So first I got all the x’s on one side and the whole numbers on the other side. So we had 2 on one side and 2x on the other. From there we divided by the number of x’s which was 2 so we can get one x only. So 2/2= 1 so x =1

6 0

3 years ago

Read 2 more answers

Find the slope of the line represented by the table of values. A.1/2 B.1 C.2 D.4

tia_tia [17]

Answer:

The correct option is A.

Step-by-step explanation:

From the given table it is noticed that the line is passing through the points (-1,1), (1,2), (3,3), (5,4) and (7,5).

Slope of a line is calculated as

$m=\frac{y_2-y_1}{x_2-x_1}$