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3 years ago

8

The social studies teacher wants to know whether the students in the entire school prefer a model United Nations activity or a s

tudent government activity. The teacher draws a random sample from the following groups: All teachers in the school All boys in each grade All students in each grade All students in the social studies club Which group best represents the population he should take a random sample from to get the best results for his survey?
All teachers in the school
All boys in each grade
All students in each grade
All students in the social studies club

1 answer:

zvonat [6]3 years ago

5 0

$Hello$ $There!$

<u>The answer is...</u>

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C. All students in each grade.

Hopefully, this helps you!!

$AnimeVines$

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I’m confused on what to do next please help

Mekhanik [1.2K]

Answer:

There are 585 adults and children

Step-by-step explanation:

Let the number of adults be a, number of children be c and the number of seniors be a

Amount made per group;

adults; 52 * a = 52a

Children : 26 * c = 26c

Seniors = 20 * s = 20s

Adding all will give 20,490

52a + 20s + 26c = 20 490 ••••(i)

Now let us work with the ratios;

a : s = 6 : 1

a/s = 6/1

a = 6s •••••(ii)

Lastly;

a/c = 4/9

4c = 9a ••••(ii)

We want to get a + c

From the first equation , let’s substitute

52(6s) + 20s + 26c = 20,490

26c = 6.5 (4c)

but 4c = 9a; 6.5(9a)

But a = 6s

So we have; 6.5(9)(6s) = 351s

so we have;

312s + 351s + 20s = 20,490

683s = 20,490

s = 20490/683

s = 30

Recall;

a = 6s = 6 * 30 = 180

4c = 9a

4c = 9 * 180

c = (9 * 180)/4 = 405

So the total number of children and adult is a + c

405 + 180 = 585

3 0

3 years ago

Given that $x \le -7,$ identify all the correct conclusions. (A) $3x \le -21.$ (B) $3x \ge -21.$ (C) $-3x \le 21.$ (D) $-3x \ge

exis [7]

Answer:

Options A and D are correct choices.

Step-by-step explanation:

We have been given an inequality $x\leq -7$ and we are asked to find the correct options from our given choices.

Let us solve inequalities in our given options one by one to see which of these matches with our given inequality.

(A) $3x\leq -21$

$x\leq \frac{-21}{3}$

$x\leq -7$

We can see that option A gives the same answer as our given inequality, therefore, option A is the correct choice.

(B) $3x\geq -21$

$x\geq \frac{-21}{3}$

$x\geq -7$

This inequality represented in option C gives solution that x should be greater than or equal to -7, which is opposite to our given inequality, therefore, option B is incorrect.

(C) $-3x\leq 21$

Dividing inequality by a negative number swaps inequality sign.

$x\geq \frac{21}{-3}$

$x\geq -7$

This inequality gives solution that x should be greater than or equal to -7, which is opposite to our given inequality, therefore, option C is incorrect.

(D) $-3x\geq 21$

Dividing inequality by a negative number swaps inequality sign.

$x\leq \frac{21}{-3}$

$x\leq -7$

We can see that option D gives the same answer as our given inequality, therefore, option D is the correct choice.

8 0

3 years ago

1. Is the square root of 2 between 1.3 and 1.4? How do you know?

VikaD [51]

Answer:

Step-by-step explanation:

1st . 1.3^2= 1.69

1.4^2= 1.96

It's not bettween 1.3 & 1.4

2. 1.4^2=1.96

1.5^2= 2.25

it's betteen 1.4 & 1.5

3 . 1.4 & 1.5 so it's eqaul 1.4

3 0

3 years ago

Read 2 more answers

Find the equation of this line

Mumz [18]

Answer:

y = 3/4x + 3

Step-by-step explanation:

Please mark me brainliest. Please I have never

been marked brainliest before.

5 0

3 years ago

hus, D satisfying (ABC)DequalsI exists. Why does the expression for D found above also satisfy D(ABC)equalsI, thereby showing

Assoli18 [71]

Complete Question

The complete question is shown on the first uploaded image

Answer:

First Question

Option A is correct

Second Question

Option C is correct

Third Question

$D = A^{-1} * B^{-1} * C^{-1}$

Fourth Question

So substituting for D in (ABC) D = I

$(ABC) * A^{-1} * B^{-1} * C^{-1} = I$

$I = I$

This proof that ABC is invertible

Step-by-step explanation:

From the question we are told that

A , B and C are invertible which means that $A^{-1} , B^{-1}, C^{-1}$ exist

Now

From the question

(ABC) D = I

Where I is an identity matrix

Now when we multiply both sides by $A^{-1}$ we have

$A^{-1} A BCD = A^{-1} * I$

$IBCD = A^{-1}$

Now when we multiply both sides by $B^{-1}$ we have

$B^{-1 } *I BCD = A^{-1} * B^{-1}$

$I CD = A^{-1} * B^{-1}$

Now when we multiply both sides by $C^{-1}$ we have

$C^{-1} * I CD = A^{-1} * B^{-1} * C^{-1}$

$I D = A^{-1} * B^{-1} * C^{-1}$

$D = A^{-1} * B^{-1} * C^{-1}$

So substituting for D in the above equation

$(ABC) * A^{-1} * B^{-1} * C^{-1} = I$

$I = I$

This proof that ABC is invertible

4 0

3 years ago