A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested. What sampling technique was used?

Answer:

D. -2/7

Step-by-step explanation:

Answer:

[tex]Equation : \ y = \frac{4}{5}x + 4[/tex]

Step-by-step explanation:

To find equation of a line we will consider two points through which the lines passes .

Let it be  ( -5 , 0 ) and ( 0 , 4 )

Step 1 : Find the slope

             [tex]slope , m = \frac{y_2 - y_1}{x_2-x_1} = \frac{0-4}{-5-0} = \frac{-4}{-5} = \frac{4}{5}[/tex]

Step 2 : Equation of the line

             [tex](y - y_1) = m(x - x_1) \\\\or \\\\(y - y_2) = m (x -x _2)[/tex]

We will use the second point ( 0. 4)

                     [tex](y - 4) = \frac{4}{5}(x - 0)\\\\y = \frac{4}{5}x + 4[/tex]

Given diameter = 1 inch

radius= D/2 = 1/2 = 0.5 inch

Circumference of circle = 2πr = 2×3.14×0.5= 3.14 inch

Answer circumference of a circle is 3.14 inch

9514 1404 393

Answer:

  152

Step-by-step explanation:

The third one is their average, so is 740/5 = 148. The largest is 4 more than that, so ...

  the largest value of the group is 152

_____

The numbers are 144, 146, 148, 150, 152.

The largest number when sum of five consecutive even integers is 740 is 152.

Numbers that follow each other continuously in the order from smallest to largest are called consecutive numbers.

Example: 1,2,3,4,5,6

                1,3,5,7,9,11

                 2,4,6,8,10,12

Difference between nearer numbers always equal

Given,

There are 5 consecutive even integers.

Then difference between each nearer number is 2

Let the first number be x

Then another 4 numbers be

(x + 2), (x + 4), (x + 6), (x + 8)

Now

According to question

(x + x + 2 + x + 4 + x + 6 + x + 8) = 740

5x = 740 - 20

x = 144

And the highest number is x + 8 = 152

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810.93

Let the pressure be given by P and the volume be V.

Since pressure is inversely proportional to volume, we can write;

P ∝ [tex]\frac{1}{V}[/tex]

=> P = [tex]\frac{c}{V}[/tex]          -------------(i)

Where;

c = constant of proportionality.

When the volume of the gas is 2 cubic feet, pressure is 1000 pounds per square foot.

V = 2 ft³

P = 1000lb/ft²

Substitute these values into equation (i) as follows;

1000 = [tex]\frac{c}{2}[/tex]

=> c = 2 x 1000

=> c = 2000 lbft

Substituting this value of c back into equation (i) gives

P = [tex]\frac{2000}{V}[/tex]

This is the general equation for the relation between the pressure and the volume of the given gas.

To calculate the work done W by the gas, we use the formula

[tex]W = \int\limits^{V_1}_{V_0} {P} \, dV[/tex]

Where;

V₁ = final volume of the gas = 3ft³

V₀ = initial volume of the gas = 2ft³

Substitute P = [tex]\frac{2000}{V}[/tex], V₁ = 3ft³ and V₀ = 2ft³

[tex]W = \int\limits^{3}_{2} {\frac{2000}{V} } \, dV[/tex]

Integrate

W = 2000ln[V]³₂

W = 2000(In[3] - ln[2])

W = 2000(0.405465108)

W = 810.93016

W = 810.93 [to 2 decimal places]

Therefore, the work done by the gas for the given pressure and volume is 810.93

Answer:

l=15

Step-by-step explanation:

let length=l

width=w

l=3w-2

w=(l+2)/3

Perimeter P=2(l+w)=2[l+(l+2)/3]=2(4l+2)/3≤43

2(4l+2)≤129

8l+4≤129

8l≤125

l≤125/8

so l=15

________________

P=2(l+w)=2(3w-2+w)=8w-4≤43

8w≤47

w≤47/8

l≤141/8-2

l≤125/8

l=15

Answer:

I guess it's False...Hope it helps you.

Answer:

true

Step-by-step explanation:

9514 1404 393

Answer:

  (a) 10

Step-by-step explanation:

Attached is a graphical solution using "substitution." An expression was written for z using the first equation, and it was substituted into the remaining two equations. This gave two equations in x and y, easily solved graphically.

We found x = 10, y = 3, so ...

  z = 3(10) -4(3) -14 = 30 -12 -14 = 4

The whole solution is (x, y, z) = (10, 3, 4).

Answer:

180

Step-by-step explanation:

Answer:

Step-by-step explanation:180

Answer:

The answer is V= ([tex]\pi[/tex]) ([tex]x-3^{2}[/tex]) (2x+7).

Step-by-step explanation:

To find the volume of the cylinder, plug in the information given in the question into the formula for the volume of a cylinder, which is V = [tex]\pi[/tex] [tex]r^{2}[/tex] h.  

Answer:

The area of a regular polygon is A = (1/2)ap, where a is the apothem and p is the perimeter of the polygon.  

The apothem is 8 inches and the perimeter is 6(7) = 42 since there are 7 sides of 6 inches.  

Then the area is

A = (1/2)(8)(42) = 336/2 = 168 in2  

I hope this helped!

Step-by-step explanation:

Mark me as brainlist pleasee

Answer:

B

Step-by-step explanation:

Find the area of the circle with r = 36/2     Area1 =  π r²

divide Area1 by two since the upper part of the figure is a semi-circle

then finally add and area of the rectangle   Area2 = (18)(36)

Total area = Area 1 + Area 2

Answer:

1156.7 cm^2

Step-by-step explanation:

for finding area of semi circle

diameter=36 cm

radius=diameter/2

=36/2

=18 cm

area of semi circle=πr^2/2

=3.14*(18)^2/2

=3.14*324/2

=1017.36/2

=508.68 cm^2

area of rectangle=length*breadth

=18 cm *36 cm

=648 cm^2

area of the figure=area of semi circle + area of rectangle

=508.68 + 648

=1156.68

=1156.7 cm^2

Explanation:

A square has all four sides the same length. So the length and width are the same.

We can see that (length)*(width) = (1/4)*(1/4) = 1/16 square miles.

If you wanted, you could solve for W in (1/4)*W = 1/16 and you should get W = 1/4.

Answer:

(x, y) = (-2,-5)

Step-by-step explanation:

Multiply the first equation by 3,and multiply the second equation by 1.

3(3x+y=−11)

1(4x−3y=7)

Becomes:

9x+3y=−33

4x−3y=7

Add these equations to eliminate y:

13x=−26

Then solve13x=−26for x:

13x=−26

13x

13

=

−26

13

(Divide both sides by 13)

x=−2

Now that we've found x let's plug it back in to solve for y.

Write down an original equation:

3x+y=−11

Substitute−2forxin3x+y=−11:

(3)(−2)+y=−11

y−6=−11(Simplify both sides of the equation)

y−6+6=−11+6(Add 6 to both sides)

y=−5

Answer:

x=−2 and y=−5

Using the Central Limit Theorem, it is found that the mean of the sample proportions would approach 0.3, hence option C is correct.

It states that for a proportion p in a sample of size n, the sampling distribution of sample proportion is approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1 - p)}{n}}[/tex], as long as [tex]np \geq 10[/tex] and [tex]n(1 - p) \geq 10[/tex].

In this problem, we have that the parameter is p = 0.3, hence the mean of the sample proportions would approach 0.3 and option C is correct.

More can be learned about the Central Limit Theorem at https://brainly.com/question/24663213

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Answer:

The answer is below

Step-by-step explanation:

The empirical rules states that for a normal distribution, 68% of the data falls within one standard deviation from the mean, 95% falls within two standard deviation from the mean and 99.7% falls within three standard deviations from the mean.

Given that:

mean (μ) = 71 inches, standard deviation (σ) = 4.3 inches

One standard deviation = μ ± σ = 71 ± 4.3 = (66.7, 75.3)

Two standard deviation = μ ± 2σ = 71 ± 2*4.3 = (62.4, 79.6)

Three standard deviation = μ ± 3σ = 71 ± 3*4.3 = (58.1, 83.9)

The graph is attached

Answer:

14

Step-by-step explanation:

84/6

Answer:

7(y intercept)

Step-by-step explanation:

y = mx +c form

y = 21-7x/3

c = 21/3 = 7(y intercept)

x i have no idea

To find x-intercept ,put y= 0 in the given eqn

So, 7x+3(0) = 21

=> 7x =21

=> x= 21/7 = 3

x-intercept = 3

Similarly, to find y-intercept put x=0 in the given eqn

So ,7(0)+3y=21

=> 3y=21

=> y= 21/3 = 7

y-intercept = 7

Answer:

598.16

Step-by-step explanation:

Eh you should have the formula if not I can't really type it but ,trust, the answer is 598.16 in²

Answer:

261.3 in.

Step-by-step explanation:

X = -1

This is because when you multiply 2 to the -1 power, it is negative because a positive times a negative is always negative. And 1/2 by the same -1 is -1/2

Answer:

2.6 2.6 2.8 2.9 2.9

Step-by-step explanation:

used median for the five numbers.

Answer:

Statement:-                   Reason:-

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Answer:

Angle RST is nowhere to be found

Step-by-step explanation:

Help us help you. Please include enough information to answer your question.

Answer:

B.35 is the value of x in the figure

Answer:

(xou)2

Step-by-step explanation:

A yacht is traveling 35° west of south at 15 miles/hour in still water. Find the component form of vector r, which represents the yacht's motion.