John asks why the last step of Pólya's four-step problem solving process, looking back, is necessary since he has already given the answer. What can you tell him?
Select all the possible reasons the last step, looking back, is necessary below.
A. Looking back allows a student to check that the answer is correct.
B. Looking back allows a student to determine the best strategy to find the solution.
C. Looking back allows a student to understand the problem.
D. Looking back allows a student to check that the answer makes sense in context of the problem.

y = p x is Proportional relationship.

What is proportional relationship?

Proportional relationships are relationships between two variables where their ratios are equivalent. Another way to think about them is that, in a proportional relationship, one variable is always a constant value times the other. That constant is know as the "constant of proportionality".

The answer depends on the equation given.

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The sample size needed is at least 311.17.

We have that to find our α level, that is the subtraction of 1 by the confidence interval divided by 2. So:

α = [tex]\frac{1-0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of 1-α

So it is z with a p-value of , so

1-0.025 = 0.975, so z = 1.96

Now, find the margin of error M as such

[tex]M = z*\frac{sd}{\sqrt{n} }[/tex]

where sd = σ = standard deviation

At least n, in which N is found when M= 0.06 and σ = 0.54. So

 [tex]M = z*\frac{sd}{\sqrt{n} } \\0.06 = 1.96 * \frac{0.54}{\sqrt{n}} \\\sqrt{n} = \frac{1.96*0.54}{0.06} \\\sqrt{n} = 17.64\\n = 311.1696\\[/tex]

Rounding off to the nearest integer, we get n = 311.17.

Thus, the sample size needed is at least 311.17.

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The value of y varies directly with x, and the constant of variation is 3, and function rule y = 3x.

When one value is dependent on another i.e if one value increases with respect to another or if one value decreases with respect to another then we can say that the two quantities are in direct variation.

In simple words,  It is the relationship between two variables where one of the variables is a constant multiple of the other.

When two values a and b are varies directly then the relation between them can be shown as given below

=> a ∝ b

=> a = kb  here 'k' constant of variation

Here we have

x values    57   63   66  

y values    19    21    22  

Let's assume that y varies directly with x  

=>  y ∝ x

=>  y = kx ---- (1)  

Where k is the proportionality constant    

From (1)

We can write k = x/y

From the above calculations, if y varies directly with x then x/y must be a constant.

Now check whether the given value can give a constant

At  x = 57 and y = 19

[tex]= > \frac{x}{y} = \frac{57}{19} = 3[/tex]  

At  x = 63 and y = 21

[tex]= > \frac{x}{y} = \frac{63}{21} = 3[/tex]  

At  x = 66 and y = 22

[tex]= > \frac{x}{y} = \frac{66}{22} = 3[/tex]    

From the above calculation,

For given x and y values, x/y is always constant

Therefore,  

It is true that y varies directly with x, and the constant of variation is 3    

Here the function rule will be  y = x × constant of variation

=> y = 3x

Therefore,

The value of y varies directly with x, and the constant of variation is 3, and function rule y = 3x

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The amount of diesel required to create slash burn fuel is = 112 gallons

The amount of gas required to create slash burn fuel = 28 gallons

What is Proportion?

The proportion formula is used to depict if two ratios or fractions are equal. The proportion formula can be given as a: b::c : d = a/b = c/d where a and d are the extreme terms and b and c are the mean terms.

Given data ,

The total amount of slash fuel = 140 gallons

The ratio of diesel to gas in slash fuel is = 8 : 2

Let the amount of diesel required to create slash burn fuel be = 8x

Let the amount of gas required to create slash burn fuel be = 2x

So , the equation of proportion is given by

Total amount of slash fuel = amount of diesel required to create slash burn fuel + amount of gas required to create slash burn fuel

Substituting the values in the equation , we get

Total amount of slash fuel = 8x + 2x

8x + 2x = 140

10x = 140

Divide by 10 on both sides of the equation , we get

x = 14 gallons

Substituting the value of x in the above expressions , we get

Amount of diesel required to create slash burn fuel = 8x

Amount of diesel required to create slash burn fuel = 8 x 14

Amount of diesel required to create slash burn fuel = 112 gallons

And ,

Amount of gas required to create slash burn fuel = 2x

Amount of gas required to create slash burn fuel = 2 x 14

Amount of gas required to create slash burn fuel = 28 gallons

Hence ,

The amount of diesel required to create slash burn fuel is = 112 gallons

The amount of gas required to create slash burn fuel = 28 gallons

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In the simple random sample, the probability that at least half of the students have brown eyes is 0.400

Probability is defined as the chance of occurrence of an event.

Probability is defined as follows:

P(E)=[tex]\frac{no of required outcome}{total of possible outcomes}[/tex]

The given parameters are:

The sample size= 30 students

Number with brown eye=40%

40% x 30 = [tex]\frac{40}{100} * 30[/tex]

=12

This means that there 12 students out of 30 that have brown eyes.

Applying the probability formula

[tex]\frac{12}{30}[/tex]= 2/5

In conclusion 0.400 of the students have brown eyes.

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The ratio of 27 feet to 8 yards is 9/8 while converting feet to yards and the ratio is also 9/8 while converting yards to feet.

Yards and feet are units use to measure the length of geometrical shapes.

1 foot equal to 0.333 yards and similarly 1 yard equal to 3 feet. There is proportional relationship between them.

We got the same fraction value from the ratio of two units which implies that the two units are proportional.

1 foot =0.333 yard so

27 feet = 9 yards

similarly, 1 yard = 3 feet

so, 8 yard = 24 feet

hence, the ratio is 9/8

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Answer:

b

Step-by-step explanation:

a variable is an unknown number normally represented by a letter and in this case the variable is b

hopes this helps please mark brainliest

a) A minimum number of dogs that could have a mass of more than 24 kg is 6.

b) The maximum number of dogs that could have a mass of more than 18 kg is 20.

We will rearrange the function using fundamental algebraic concepts to process the value of x when the derivative equals 0. This response gives  us the x-coordinate of the function's vertex, which is the point that  the maximum or minimum will occur. To find the minimum or maximum, we will start by rewriting the solution into the original function.

From the given parameters, we can see that the minimum of the values present in the interval 20 to 40 is 6

From the given parameters, we can see that the maximum of the values present in the interval 20 to 40 is;

(12 + 6) = 18

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Answer:

[tex] 2 \sqrt[3] {60}~mm [/tex]

Step-by-step explanation:

The volume of a cube is the side cubed, so each edge is the cubic root of the volume.

V = 480 mm³

[tex] s = \sqrt[3] {V} [/tex]

[tex] s = \sqrt[3] {480~mm^3} [/tex]

[tex] s = \sqrt[3] {2^3 \times 2^2 \times 3 \times 5~mm^3} [/tex]

[tex] s = \sqrt[3] {2^3} \times \sqrt[3] {2^2 \times 3 \times 5~mm^3} [/tex]

[tex] s = 2 \sqrt[3] {60}~mm [/tex]

Answer: $11.94

Step-by-step explanation: 4 x 0.99 = $3.96 and then 2 x $3.99 = $7.98 now $7.98 + $3.96 = $11.94

The equation of a line that is parallel to -x + 3y = 6 and passes through the point (3,5) is y = 1 / 3 x + 5

The equation of a line can be represented in slope intercept form as follows:

y = mx + b

where

Therefore, the equation of a line that is parallel to -x + 3y = 6 and passes through the point (3,5) can be found as follows:

Parallel lines have the same slope.

-x + 3y = 6

3y = x + 6

y = 1  / 3 x + 2

Therefore, the slope is 1 / 3. Let's find the y-intercept using (3, 5).

y = 1 / 3 x + b

5 = 1 / 3 (3) + b

b = 5

Therefore, the equation is y = 1 / 3 x + 5

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The equivalent expression is  2x² - 7x + 7

Option A is the correct answer.

An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.

Example:

2 + 3x + 4y = 7 is an expression.

2x + 6 - 9 is an expression.

3x = 9 is an expression.

We have,

(3x² - 2x + 2) - (x² + 5x - 5)

Remove the parenthesis.

3x² - 2x + 2 - x² - 5x + 5

Add like terms.

2x² - 2x + 2 - 5x + 5

Add like terms

2x² - 7x + 7

Thus,

The final expression is 2x² - 7x + 7

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Answer: Choice A, Choice B, Choice C

In other words, it's nearly everything but choice D.

====================================================

Explanation:

Let's say we select "2" as the thing to fill the blank.

2x+3 = -4x+17

2x+4x = 17-3

6x = 14

x = 14/6

x = 7/3

We get one solution in this case.

The same applies for the values 5 and 7. I'll let you do those steps.

In contrast, if we filled the blank with -4, then,

-4x+3 = -4x+17

-4x+4x = 17-3

0x = 14

0 = 14

We get a contradiction which leads to "no solutions".

Visually, the equations y = -4x+3 and y = -4x+17 are parallel lines that never intersect. We need them to intersect if we want a solution. Recall that parallel lines have equal slopes but different y-intercepts. Both sides have a slope of -4 in this case.

Therefore, the quick rule of thumb is this: if the slopes are not equal, then the linear equation has exactly one solution.

The true or false values of the statements are:

From the question, we have the following parameters that can be used in our computation:

C(m) = 4.50m + 7

The smallest number of mugs she can sell is 0

So, we have the following equation

C(0) = 4.50 * 0 + 7

Evaluate

C(0) = 0

This means that the range is y ≥ 0

Next, the domain cannot be all real numbers

This is because real numbers include negative and decimal numbers

For the y-intercept, we have

C(m) = 4.50m + 7

Set m to 0

y-intercept = 4.5 * 0 + 7

Evaluate

y-intercept = 7

For the y-intercept, we have

C(m) = 4.50m + 7

Set C(m) to 0

4.5 * x-intercept  + 7 = 0

Evaluate

x-intercept = -7/4.5 -- this cannot be taken as the x-intercept  because it is a negative number

Also, we have the slope to be 4.5

So, the rate of change is $4.5 per mug

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The equation of the ellipse is x²/8² + y²/(2√15)² = 1.

An equation is a mathematical statement that is made up of two expressions connected by an equal sign.

Example:

2x + 4 = 9 is an equation.

We have,

Foci: (-2, 0) and (2, 0)

Length of major axis: 8

The equation of an ellipse.

x²/a² + y²/b² = 1

Where a is the major axis and b is the minor axis.

Now,

b² + c² = a²

c = 2

a = 8

b² = a² - c²

b² = 64 - 4

b² = 60

b = √60

b = √(4 x 15)

b = 2√15

Now,

x²/a² + y²/b² = 1

x²/8² + y²/(2√15)² = 1

Thus,

The ellipse equation is x²/8² + y²/(2√15)² = 1.

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The greatest common factor of 40 and 24 would be; 8.

Expression in maths is defined as the collection of numbers variables and functions by using signs like addition, subtraction, multiplication, and division.

We can rewrite this expression for distribution using the amount of times 8 goes into both numbers as;

8(5 + 3)

Using the distributive property, we get:

8(5) + 8(3) = 40 + 24.

Threfore,

The greatest common factor of 40 and 24 would be; 8.

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Answer:

D

Step-by-step explanation:

3x - 2y = 10 → (1)

2y = 3x - 16 → (2)

substitute 2y = 3x - 16 into (1)

3x - (3x - 16) = 10

3x - 3x + 16 = 10

16 = 10 ← not possible

this indicates the system has no solution.

There is no solution to this system. Therefore, option D is the correct answer.

A system of linear equations consists of two or more equations made up of two or more variables such that all equations in the system are considered simultaneously. The solution to a system of linear equations in two variables is any ordered pair that satisfies each equation independently.

The given that the system of linear equations are

3x - 2y = 10 -------(i)

2y = 3x - 16

3x-2y=16 -------(ii)

Subtract equation (ii) from equation (i), we get

3x-2y-(3x-2y)=10-16

0≠4

Therefore, option D is the correct answer.

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is that even a question bro?

To find the slope of a line that passes through two points, you can use the formula:

slope = (y2 - y1)/(x2 - x1)

In this case, the two points are (0,0) and (1/3, 7/3). Substituting these values into the formula, we get:

slope = (7/3 - 0)/(1/3 - 0)

slope = 7/3

Therefore, the slope of the line that passes through (0,0) and (1/3, 7/3) is 7/3.

Answer:

x = 3

Step-by-step explanation:

You want to solve for x, so you want to get x on one side of the equation. To do this, you can add the -12.18 to both sides of the equation (you add since it's negative).

2.14x - 12.18 = -5.76

2.14x = 6.42

Then you want to get x by itself, without the 2.14 in front of it. To do this, you can divide both sides of the equation by 2.14.

This will give you,

x = 3

Answer:

Pie heysgeusuwhueywgyssyywyw

Answer:

Imma write it in the explanation

Step-by-step explanation:

6. interior angles, alternate angles

for c to be parallel with d, we need 2 and 7 to be interior angles (a+b=180°, u/c shaped), and 3 and 5 to be alternate angles (a=b, z shaped).

7. 1+3=180°, 2+4=180°

there were 2 parallel lines in a trapezium, so for the c shape on 1 and 3 they add up to 180°, and same thing to 2 and 4.

(a) For positive Linear Regression , Y score will be above mean .

(b) For negative Linear Regression , Y score will be below the mean .

What is Linear Regression ?

The term Linear regression analysis is used to predict the value of one  variable based on the value of another variable.

Part(a)

when the relationship of regression between two variables is positive then if one variable increase the other variable also increases ,

So , if the the x score is above the mean then the Y score will be also above the mean .

Part(b)

when the relationship of regression between two variables is negative then if one variable increase the other variable decreases ,

So , if the the x score is above the mean then the Y score will be below the mean .

Therefore , (a) Y score will be above the mean .

(b) the Y score will be below the mean .

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Answer: 13h

Step-by-step explanation:

126 + 20 = 146
250 - 146 = 104
104 : 8 = 13

He will need 13h

Answer:

13.5

126 plus 20 is $146

250 minus 146 is 108

108 divided by 8 is 13.5

Answer:

x = -3

Step-by-step explanation:

0.2x + 2 = 0.2(4 - x)

0.2x + 2 = 0.8 - 0.2x

0.4x = -1.2

x = -1.2/0.4

x = -3

Forever c x stays in the set but x+y may be out side the set.

What is set?

A set comprises elements or members that can be mathematical objects of any sort, including numbers, symbols, points in space, lines, other geometric forms, variables, or even other sets. A set is the mathematical model for a collection of various things.

a consider the set of vectors in [tex]$\mathbb{R}^2$[/tex]

[tex]A=\left\{\left(x_1, x_2\right) \in \mathbb{R}^2 \mid x_2 \geqslant 2\right\} .$$[/tex]

where[tex]$x=\left(x_1, x_2\right)$[/tex]

Then for any [tex]$x=\left(x_1, x_2\right), y=\left(y_1, y_2\right) \in A$[/tex]

ere that[tex]$x+y=\left(x_1+y_1, x_2+y_2\right) \in A\left(\right.$ Since $x_2+y_2 \geqslant 2+2$[/tex]

But take [tex](4,2) \in A$.[/tex]

Then [tex]\frac{1}{2}(4,2)=(2,1) \notin A$.[/tex]

ce. [tex]$\frac{1}{2}(4,2)$[/tex] belongs outside the set

i.. I some vectors in A such that[tex]\frac{1}{2} x \notin A$[/tex].

b Consider the set of vectors in [tex]$\mathbb{R}^2$[/tex]

[tex]A=\left\{\left(x_1, x_2\right) \in \mathbb{R}^2 \mid \begin{array}{ll}\frac{1}{2} x_1 \leq x_2 \leq \frac{3}{2} x_1 & \text { if } x_1 \geqslant 0 \\\frac{3}{2} x_1 \leq x_2 \leq \frac{1}{2} x_1 & \text { if } x_1 < 0\end{array}\right\}$$[/tex]

The geometrical representation of this set is

see that for any scalar [tex]$c, \quad c x=e\left(x_1, x_2\right) \in A$[/tex]. But if we take [tex](3,2) *(-2,3-3) \in A$ but $(3,2)+(-2,-3)=(1,-1) \& A$[/tex].

Thus forever c x stays in the set but x+y may be out side the set.

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Option D is the correct answer. Paired samples t-test is the same as the dependent t-test, but different from one sample z-test.

The dependent t-test also called the paired t-test or paired-samples t-test compares which means the two related groups to determine whether there is a statistically significant difference between these means.

The T-test is defined as a univariate hypothesis test that is based on a t-statistic, On the other side, Z-test is also a univariate test that is based on a standard normal distribution.

There is a small comparison between the t-test and z-test:

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With the mid segment of the triangle MNP as M (-1, 3), N (4, 0), P (-2, -2) the coordinates of the triangle are

The coordinates is calculated from the midsegment using the formula

X= (x₂ + x₁)/2

Y = (y₂ + y₁)/2

Vertex 1 and 2: point  M  (-1, 3),  

X

-1 = (x₂ + x₁)/2

-2 = x₂ + x₁

Y

3 = (y₂ + y₁)/2

6 = y₂ + y₁

Vertex 2 and 3:  point N (4, 0)

X

4 = (x₂ + x₃)/2

8 = x₂ + x₃

Y

0 = (y₂ + y₃)/2

0 = y₂ + y₃

Vertex 1 and 3:  point P(-2, -2)

X

-2 = (x₃ + x₁)/2

-4 = x₃ + x₁

Y

-2 = (y₃ + y₁)/2

-4 = y₃ + y₁

The equations

X

-2 = x₂ + x₁

8 = x₂ + x₃

-4 = x₃ + x₁

Y

6 = y₂ + y₁

0 = y₂ + y₃

-4 = y₃ + y₁

from -2 = x₂ + x₁, we find x₁ = -2 - x₂

plugging in x₁ = -2 - x₂ to -4 = x₃ + x₁ gives

-4 = x₃ + -2 - x₂

-2 = x₃ - x₂

then we have

8 = x₂ + x₃

-2 = x₃ - x₂

solving simultaneously

x₃ = 3, x₂ = 5 then x₁ = -2 - x₂ = -7

from 0 = y₂ + y₃, we find that y₂ = -y₃

plugging in y₂ = -y₃ into 6 = y₂ + y₁ gives

6 = -y₃ + y₁

then we have

-4 = y₃ + y₁

6 = -y₃ + y₁

solving simultaneously gives

y₁ = 1, y₃ = -5, then y₂ = -y₃ = -(-4) = 5

The vertex of the triangle are

(-7, 1), (5, 5), and (3, -5)

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