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3 years ago

Can someone please help me?!?!?!?

Mathematics

1 answer:

Pie3 years ago

4 0

Answer:You havent attached anything to youre question.

Step-by-step explanation:

You need to attach someone so people can help you.

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A Lake Tahoe Community College instructor is interested in the mean number of days Lake Tahoe Community College math students ar

Ipatiy [6.2K]

Answer:

She used the simple random sampling technique because there was no condition attached to the samples she took.

Step-by-step explanation:

we have basically four types of sampling

1.Simple random sampling.

2.Systematic sampling.

3.Stratified sampling.

4.Cluster sampling.

simple Random sampling: is a sampling technique where every item in the population has an even chance and likelihood of being selected in the sample.

6 0

3 years ago

You are constructing a concrete landing pad for a helicopter. You have 4704 cubic feet of concrete.

MAVERICK [17]

a) We have to calculate the height of the pad.

We know that the volume will be 4704 cubic feet.

We also know that the base of the pad is a square of side length 56 feet.

As the volume is the area of the base times the height, we can find the height by dividing the volume by the base area:

$\begin{gathered} V=A_b\cdot h \\ h=\frac{V}{A_b}=\frac{4704\text{ ft}^3}{(56\text{ ft})^2}=\frac{4704}{3136}\text{ ft}=1.5\text{ ft} \end{gathered}$

The height is 1.5 feet.

b) Now, we have a circular pad of which we know the height (1.5 feet) and the volume (4705 ft³). The area of the base will have to be the same as the are of the square: 3136 ft².

The area of this circular pad can be expressed as πD²/4, so we can calculate the diameter D as:

$\begin{gathered} A=3136 \\ \frac{\pi D^2}{4} \\ D^2=3136*\frac{4}{\pi} \\ D^2=3136*\frac{4}{3.14} \\ D^2=3994.9045 \\ D=\sqrt{3994.9045} \\ D\approx63.21 \end{gathered}$

The diameter is approximately 63.21 feet.

Answer:

a) The pad will be 1.5 feet thick

b) The diameter will be 63.21 feet.

3 0

1 year ago

Find the general solution to 1/x dy/dx - 2y/x^2 = x cos x, y(pi) = pi^2

Finger [1]

Answer:

$\frac{y}{x^2}=\sin x+\pi$

Step-by-step explanation:

Consider linear differential equation $\frac{\mathrm{d} y}{\mathrm{d} x}+yp(x)=q(x)$

It's solution is of form $y\,I.F=\int I.F\,q(x)\,dx$ where I.F is integrating factor given by $I.F=e^{\int p(x)\,dx}$ .

Given: $\frac{1}{x}\frac{\mathrm{d} y}{\mathrm{d} x}-\frac{2y}{x^2}=x\cos x$

We can write this equation as $\frac{\mathrm{d} y}{\mathrm{d} x}-\frac{2y}{x}=x^2\cos x$

On comparing this equation with $\frac{\mathrm{d} y}{\mathrm{d} x}+yp(x)=q(x)$ , we get $p(x)=\frac{-2}{x}\,\,,\,\,q(x)=x^2\cos x$

I.F = $e^{\int p(x)\,dx}=e^{\int \frac{-2}{x}\,dx}=e^{-2\ln x}=e^{\ln x^{-2}}=\frac{1}{x^2}$ { formula used: $\ln a^b=b\ln a$ }

we get solution as follows:

$\frac{y}{x^2}=\int \frac{1}{x^2}x^2\cos x\,dx\\\frac{y}{x^2}=\int \cos x\,dx\\\\\frac{y}{x^2}=\sin x+C$

{ formula used: $\int \cos x\,dx=\sin x$ }

Applying condition: $y(\pi)=\pi^2$

$\frac{y}{x^2}=\sin x+C\\\frac{\pi^2}{\pi}=\sin\pi+C\\\pi=C$

So, we get solution as :

$\frac{y}{x^2}=\sin x+\pi$

4 0

3 years ago

In a market research survey of 2518 motorists, 252 said that they made an obscene gesture in the previous month.

Lelechka [254]

Answer:

Probability is 89.99%

Step-by-step explanation:

divide 252 by 2518 and you get 10.01% but that represents the people who did make the gesture so instead you would minus 252 from 2518 and that would be 252 - 2518 = 2266 then you would divide 2266 by 2518 and you get 2266/2518 = 0.8999 which is equal to 89.99%

4 0

2 years ago

Please help w geometry thanks babes 1-4 30pts

juin [17]

1- Notice that it's a right triangle (inscribed in 1/2 circle)

Then 2x+3x-5 + 90°° =180°===> x=10°

2- the 2 cords are equal then the triangle is isosceles & one these angle is equal to 95/2 = 47.5°°. Then 2 x 47.5 + x=180 ==> x =85°

3- Internal angle to a cercle: 88°=(x°+44°)/2===>66°

4- External angle to a cercle: x° = (160°-15°)/2===>72.5°

8 0

4 years ago

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