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Morgarella [4.7K]

3 years ago

7

What is a cluster sample?

1 answer:

fgiga [73]3 years ago

4 0

This is a sampling technique used when natural groupings are evident in a statistical population. It is often used in marketing research.

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rue or false: It is common to denote random variables by upper-case letters and particular values of the random variables by the

jolli1 [7]

Answer:

true

Step-by-step explanation:

5 0

2 years ago

What point will y+4x=-24 and x=3y-45 intersect

rewona [7]

Solve as simultaneous equations or substitute for the x or y value, and then get the other x or y value by substituting.

Substitution method:

y + 4x = -24
x = 3y - 45

Substitute the x into the first equation.

y + 4 (3y-45) = -24

Simplify and solve for y

y + 12y - 180 = -24
13y = -24 + 180
13y = 156
y = 12

Substitute y into one of the equations to find the x value.

x = 3(12) - 45
x = -9

(-9,12) is where the lines intersect.

7 0

3 years ago

will spent 24 min putting together a model plane then he spent 48 minutes painting the model how long did will spend working on

kifflom [539]

24 + 48 = 72 minutes

Or, one hour and 12 minutes

3 0

4 years ago

Read 2 more answers

According to the AAMA Code of Ethics, members of the AAMA should always

musickatia [10]

The answer should be B

4 0

4 years ago

Read 2 more answers

a. Calculate the volume of the solid of revolution created by rotating the curve y = 3 + 3 exp(-5 x) about the x-axis, for x bet

miskamm [114]

Answer:

A) The volume of solid is 18π cubic unit.

B) The volume of sphere is $\dfrac{4}{3}\pi r^3$

a = -r , b = r , $f(x)=\sqrt{r^2-x^2}$ and $V=\dfrac{4}{3}\pi r^3$

Solution A)

The given curve, $y=3+3e^{-5x}$ rotate about x-axis between 2 to 4.

Please find attachment for solid figure or rotation.

Using disk method to find the volume rotation about x-axis

$V=\int_a^b\pi R^2dx$

where, a = 2, b= 4 , $R=y=3+3e^{-5x}$ and dx is thickness of disk.

$V=\int_2^4\pi (3+3e^{-5x})^2dx$

$V=9\pi\int_2^4(1+e^{-10x}+2e^{-5x})dx$

$V=9\pi(x-\dfrac{1}{10}e^{-10x}-\dfrac{2}{5}e^{-5x})|_2^4)$

$V=9\pi(4-\dfrac{1}{10}e^{-40}-\dfrac{2}{5}e^{-20}-2+\dfrac{1}{10}e^{-20}-\dfrac{2}{5}e^{-10}))$

$V=9\pi (2-0)$

$V=18\pi$

Hence, the volume of solid is 18π cubic unit

Solution B)

The equation of circle of radius r and centered at origin (0,0).

$x^2+y^2=r^2$

$y=\sqrt{r^2-x^2}$

The solid form is sphere of radius r.

Using disk method, to find volume of solid

$V=\int_a^b\pi R^2dx$

where, a = -r, b = r , $R=y=\sqrt{r^2-x^2}$ and dx is thickness of disk.

$V=\int_{-r}^r\pi (r^2-x^2)dx$

$V=\pi(r^2x-\dfrac{x^3}{3})|_{-r}^r$

$V=\pi(2r^3-\dfrac{2r^3}{3})$

$V=\dfrac{4}{3}\pi r^3$

Hence, the volume of sphere is $\dfrac{4}{3}\pi r^3$

4 0

4 years ago