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3 years ago

Need help somebody help me plz

Mathematics

1 answer:

Wewaii [24]3 years ago

5 0

Hello,
The formula for finding the circumference of a circle is $2 \pi r$ where r is the radius. SO we can plug 4 in for r in this formula because 4 is the radius: $2 \pi 4=8 \pi$ . We are told to use 3.14 for $\pi$ so we get $8(3.14)=25.12$ . Therefore, the circumference is 25.12 meters.

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If a and b are positive constants and if a(x-y) = b(y-x), what is the value of the ratio of x/y?

Mekhanik [1.2K]

Answer: x/y=1

Step-by-step explanation:

a(x-y)=b(y-x)

(a+b)x=(a+b)y

x/y=1 ans

hope this helps

8 0

3 years ago

In a survey of 12 people, it was found that an average of $36 was spent on their child's last birthday gift with a standard devi

Nataliya [291]

Answer:

(27.3692 ; 44.6308)

Step-by-step explanation:

Mean, xbar = 36

Standard deviation, s = 11

Sample size, n = 12

Tcritical at 0.2, df = 12 - 1 = 11 ; Tcritical = 2.718

Confidence interval :

Xbar ± Margin of error

Margin of Error = Tcritical * s/sqrt(n)

Margin of Error = 2.718 * 11/sqrt(12) = 8.6308

Confidence interval :

Lower boundary : 36 - 8.6308 = 27.3692

Upper boundary : 36 + 8.6308 = 44.6308

(27.3692 ; 44.6308)

3 0

3 years ago

Which is one way to check 102 ÷ 6 = 17

Nikolay [14]

The answer is B. 100/5=20 hope i helped

3 0

3 years ago

What’s #1?????? Plz help

liq [111]

Answer:

C) $400\pi$

Step-by-step explanation:

The formula for area is

A=pi * radius ^2

If the diameter is 40, the radius is 20

Therefore

$A=\pi 20^{2} \\A=\pi 400$

7 0

2 years ago

(I've been trying to figure this out for 3 days and I really need help)

liq [111]

Check the picture below.

since the diameter of the cone is 6", then its radius is half that or 3", so getting the volume of only the cone, not the top.

$\bf \textit{volume of a cone}\\\\ V=\cfrac{\pi r^2 h}{3}~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ r=3\\ h=4 \end{cases}\implies V=\cfrac{\pi (3)^2(4)}{3}\implies V=12\pi \implies V\approx 37.7$

now, the top of it, as you notice in the picture, is a semicircle, whose radius is the same as the cone's, 3.

$\bf \textit{volume of a sphere}\\\\ V=\cfrac{4\pi r^3}{3}~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=3 \end{cases}\implies V=\cfrac{4\pi (3)^3}{3}\implies V=36\pi \\\\\\ \stackrel{\textit{half of that for a semisphere}}{V=18\pi }\implies V\approx 56.55$

well, you'll be serving the cone and top combined, 12π + 18π = 30π or about 94.25 in³.

pretty much the same thing, we get the volume of the cone and its top, add them up.

$\bf \stackrel{\textit{cone's volume}}{\cfrac{\pi (3)^2(8)}{3}}~~~~+~~~~\stackrel{\stackrel{\textit{half a sphere}}{\textit{top's volume}}}{\cfrac{4\pi 3^3}{3}\div 2}\implies 24\pi +18\pi \implies 42\pi ~~\approx~~131.95~in^$

8 0

3 years ago