i'm so confused! what answer am i missing???

(the first picture is the question)

(the second picture is the answers)

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What I gather from the question is that [tex]X[/tex] has second moment [tex]E(X^2)=81[/tex] and variance [tex]V(X) = 58[/tex], and you're asked to find the expectation and variance of the random variable [tex]Y=2X+10[/tex].

From the given second moment and variance, we find the expectation of [tex]X[/tex] :

[tex]V(X) = E(X^2) - E(X)^2 \implies E(X) = \sqrt{E(X^2) - V(X)} = \sqrt{23}[/tex]

Expectation is linear, so

[tex]E(Y) = E(2X+10) = 2 E(X) + 10 = \boxed{2\sqrt{23} + 10}[/tex]

Using the same variance identity, we have

[tex]V(Y) = V(2X+10) = E((2X+10)^2) - E(2X+10)^2[/tex]

and

[tex]E((2X+10)^2) = E(4X^2 + 40X + 100) = 4E(X^2) + 40E(X) + 100 = 424 + 40\sqrt{23}[/tex]

so that

[tex]V(Y) = V(2X+10) = (424 + 40\sqrt{23}) - (2\sqrt{23} + 10)^2 = \boxed{232}[/tex]

Alternatively, we can use the identity

[tex]V(aX+b) = a^2 V(X) \implies V(2X+10) = 4V(X) = 232[/tex]

Answer:

7.  Down 5

8.  Horizontal reflection

9.  Vertical stretch by a factor of 5

Step-by-step explanation:

Transformations of Graphs (functions) is the process by which a function is moved or resized to produce a variation of the original (parent) function.

Transformations

For a > 0

[tex]f(x+a) \implies f(x) \: \textsf{translated}\:a\:\textsf{units left}[/tex]

[tex]f(x-a) \implies f(x) \: \textsf{translated}\:a\:\textsf{units right}[/tex]

[tex]f(x)+a \implies f(x) \: \textsf{translated}\:a\:\textsf{units up}[/tex]

[tex]f(x)-a \implies f(x) \: \textsf{translated}\:a\:\textsf{units down}[/tex]

[tex]y=a\:f(x) \implies f(x) \: \textsf{stretched parallel to the y-axis (vertically) by a factor of}\:a[/tex]

[tex]y=f(ax) \implies f(x) \: \textsf{stretched parallel to the x-axis (horizontally) by a factor of} \: \dfrac{1}{a}[/tex]

[tex]y=-f(x) \implies f(x) \: \textsf{reflected in the} \: x \textsf{-axis}[/tex]

[tex]y=f(-x) \implies f(x) \: \textsf{reflected in the} \: y \textsf{-axis}[/tex]

Identify the transformations that take the parent function to the given function.

Question 7

[tex]\textsf{Parent function}: \quad f(x)=x^3[/tex]

[tex]\textsf{Given function}: \quad f(x)=x^3-5[/tex]

Comparing the parent function with the given function, we can see that 5 has been subtracted from the parent function.

Therefore, the transformation is:

[tex]f(x)-5 \implies f(x) \: \textsf{translated}\:5\:\textsf{units down}[/tex]

Question 8

[tex]\textsf{Parent function}: \quad f(x)=x^3[/tex]

[tex]\textsf{Given function}: \quad f(x)=-x^3[/tex]

Comparing the parent function with the given function, we can see that the parent function has been multiplied by -1.

Therefore, the transformation is:

[tex]y=-f(x) \implies f(x) \: \textsf{reflected in the} \: x \textsf{-axis}[/tex]

Question 9

[tex]\textsf{Parent function}: \quad f(x)=x^3[/tex]

[tex]\textsf{Given function}: \quad f(x)=5x^3[/tex]

Comparing the parent function with the given function, we can see that the parent function has been multiplied by 5.

Therefore, the transformation is:

[tex]y=5\:f(x) \implies f(x) \: \textsf{stretched parallel to the y-axis (vertically) by a factor of}\:5[/tex]

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Answer:

7. Down 5

8. Horizontal Reflection.

9. Vertical Stretch by a factor of 5.

Explanation:

Parent function: f(x) = x^3

7. f(x)= x^3 - 5

Comparing it with f(x) - d which gives function shifted d units down.

Here the function has shifted 5 units down.

8. f(x)= -x^3

Comparing with -f(x) gives reflection over x-axis (horizontal reflection).

Here the function f(x) = (-1x^3) has been reflected horizontally.

9. f(x)= 5x^3​

Comparing with a(f(x)) gives vertical stretch when |a| > 1 or compression when 0 < |a| < 1 by a factor of a.

Here the function f(x) = 5x^3​ has been vertically stretched by a factor of 5.

Answer:

1800 m

Step-by-step explanation:

1 km = 1000 m

1.8 km = 1.8 × 1 km = 1.8 × 1000 m = 1800 m

The amount in lee's mutual fund account after 8 years will be $7600

Given: Principal amount (P) = $5000,

Time (t) = 10 years,

Rate of interest (r) = 6.5% per year

To find: lee's mutual fund account after only 8 years

We know that Simple interest (SI) is given by:

[tex]S.I = \frac{PTR}{100}[/tex].......(1)

So, by using equation (1) money (P') in a mutual fund account after 8 years will be

[tex]P'=P+\frac{PTR}{100}[/tex]

[tex]=5000+\frac{5000*6.5*8}{100}[/tex]

[tex]= 5000+50*6.5*8[/tex]

= 5000+2600

= 7600

Hence, the amount in lee's mutual fund account after 8 years will be $7600

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Answer:

A

Step-by-step explanation:

The graph is composed of two different rays.

Also, when x = -2, there is an open hole.

This leaves A as the answer.

Rationalizing the denominator and simplifying the expression, the result is 6√5 + 13.

Option C is the correct answer.

Given that;

[tex]\frac{4+\sqrt{5} }{\sqrt{5} -2}[/tex]

To rationalize the denominator, we multiply the expression by [tex]\frac{\sqrt{5} +2 }{\sqrt{5} +2}[/tex]

Hence

[tex]\frac{4+\sqrt{5} }{\sqrt{5}-2 } *\frac{\sqrt{5} +2 }{\sqrt{5} +2}\\\\\\\frac{(4+\sqrt{5}) }{(\sqrt{5}-2) } \frac{(\sqrt{5} +2) }{(\sqrt{5} +2)}\\\\\\\frac{(4+\sqrt{5})(\sqrt{5}+2) }{\sqrt{5}^2+\sqrt{5}*2-2\sqrt{5} -4 } \\\\\\\frac{(4+\sqrt{5} )(\sqrt{5}+2 )}{1}\\ \\(4+\sqrt{5} )(\sqrt{5}+2 )\\\\4\sqrt{5}+4*2+\sqrt{5}\sqrt{5}+\sqrt{5}*2\\ \\ 4\sqrt{5}+8+5+2\sqrt{5}\\ \\ 6\sqrt{5}+13[/tex]

Rationalizing the denominator and simplifying the expression, the result is 6√5 + 13.

Option C is the correct answer.

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Answer:

3

Step-by-step explanation:

using the power we multiply the exponents (27^1/2)^2/3 to get 27^1/3=3

The mistaken assumption is that the customer thinks the shoes are back to their original price.

The assumption is wrong because the price of the shoe is now lower than $150.

The cost of the shoe now is $126.

In order to retain the price of $150, the percentage decrease should have been 28.6%.

Price of the shoe after it was increased : 1.4 x 150 = 210

Price of the shoe after it was decreases: (1 - 0.4) x 210

0.6 x 210 = $126

The percentage the price should be decreased for the price to be back to $150 = (150 / 210) - 1 = 28.9%

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Answer:

159

Step-by-step explanation:

all natural numbers are numbers that go above 0 and etc…

Therefor, 256 - 97

= 159

Answer:

158

Step-by-step explanation:

Between means 97 and 256 are not included

Therefore its should be:

=(256-97)-1

=158

The inequality of the given graph in Slope Intercept Form is;

y ≥ 3x - 2

From the attached graph, we see that the boundary line passes through the points (0,-2) and (1,1), and as such the equation of the boundary line is gotten from the general formula;

(y - y1)/(x - x1) = (y2 - y1)/(x2 - x1)

Thus, we have;

(y + 2)/(x - 0) = (1 + 2)/(1 - 0)

(y + 2)/x = 3

y + 2 = 3x

y = 3x - 2

Now, the boundary line is a solid line and the shaded area lies above the boundary line, therefore the sign of inequality must be ≥.

The inequality of the given graph in Slope Intercept Form is;

y ≥ 3x - 2

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Answer:

  x + 10

Step-by-step explanation:

You want to know how much money Joyce has if she won a bet with George in which they both started with the same money, both bet 5 cents, and George ended up with x cents.

We assume that both Joyce and George put 5 cents in the pool. After doing that, each had x cents. If Joyce won the 10-cent pool, she now has ...

  x + 10 cents

__

Additional comment

If they both bet against a house, or in a situation where a third party was involved, the amount Joyce ends with depends on the odds of the game, or the percentage collected by the house.

Given that the game is not specified, we have made up the rules.

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The missing algebra property justification for the equation solution is; Multiplicative Inverse

We are given the equation;

2x - 7 = 15

Step 1; Add 7 to both sides to get; 2x - 7 + 7 = 15 + 7

2x = 22

Reason; Addition property of equality

Step 2; Multiply both sides by 1/2(one half) to get;

(1/2) * 2x = (1/2) * 22

x = 11

Reason; Multiplicative Inverse

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Answer:

Step-by-step explanation:

Hello!

15 < x + 4

We can subtract 4 from both sides, to cancel it out.

15 - 4 is 11.

11 < x

x = {12,13,14,15,16,..........................................................................Infinity}

Hope I Helped!

The difference between the rate of change of B and the rate of change of A is 15.

First, we need to get the two rates of change.

We have two linear functions.

A: y = 35*x

For function A the rate of change is the slope, wich is 35.

Function B is graphed.

Remember that if a line passes through two points (x₁, y₁) and (x₂,y₂) then the slope is:

[tex]a = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

In the graph, we can see that line B passes through (0, 0) and (1, 50), then the slope is:

[tex]a = \frac{50 - 0}{1 - 0} = 50[/tex]

Then the rate of change of B is 50.

The difference between the rates of change is:

diff = 50 - 35 = 15

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The area of a 2D form is the amount of space within its perimeter. The length of the rectangle is 29 inches and the width of the rectangle is 12 inches.

The area of a 2D form is the amount of space within its perimeter. It is measured in square units such as cm², m², and so on. To find the area of a square formula or another quadrilateral, multiply its length by its width.

Let the width of the sheet be represented by x and the length be represented by y.

Area = x × y

348 = xy

x = 348/y

Perimeter = 2(x+y)

82 = 2(x+y)

41 = x + y

41 = (348/y) + y

0 = y² - 41y + 348

y = 29, 12

Therefore, the length of the rectangle is 29 inches and the width of the rectangle is 12 inches.

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Final answer:

The answer is 10.65.

Step-by-step explanation:

Step 1

Substitute a=1,5 into expression

7.1a, a=1.5

7.1 x 1.5

Step 2

Multiply the numbers

7.1 x 1.5 = 10.65

Answer:

10.65

Step-by-step explanation:

Plug a into the expression

[tex]7.1\times1.5=10.65[/tex]

Hope I helped you in some way!

For convenience sake, I will let [tex]y=f(x)=9e^{x}\sin x[/tex]

First, we evaluate the function at the endpoints of the interval.

[tex]f(0)=9e^{0}\sin(0)=0\\\\f(\pi)=9e^{\pi}\sin(\pi)=0[/tex]

Then, we need to find the critical points.

We can start by taking the derivative using the power rule.

[tex]f'(x)=9e^{x} \frac{d}{dx} \sin x+9\sin x \frac{d}{dx} e^{x}=9e^{x}(\cos x+\sin x)[/tex]

Setting this equal to 0,

[tex]9e^x (\cos x+\sin x)=0[/tex]

Since [tex]9e^x > 0[/tex], we can divide both sides by [tex]9e^x[/tex].

[tex]\cos x+\sin x=0\\\\\sin x=-\cos x\\\\\tan x=-1\\\\x=\frac{3\pi}{4}[/tex]

[tex]f\left(\frac{3\pi}{4} \right)=9e^{3\pi/4}\sin \left(\frac{3\pi}{4} \right)=\frac{9\sqrt{2}e^{3\pi/4}}{2}[/tex]

So, the absolute minimum is [tex]\boxed{\left(\frac{3\pi}{4}, \frac{9\sqrt{2}e^{3\pi/4}}{\sqrt{2}} \right)}[/tex] and the absolute minima are [tex]\boxed{(0,0), (\pi, 0)}[/tex]

Answer:

Using the formulas

C=2πr

d=2r

Solving for d

d=C

π=8

π≈2.54648

d≈2.55

Answer:

35

Step-by-step explanation:

This shape has 6 sides.

Sum of interior angles of a 6 sided shape is 720.

117 + 4x - 5 + 4x - 3 + 118

+ 3x + 6 + 3x - 3 = 720

4x + 4x + 3x + 3x

+ 117 + 118 + 6 - 5 - 3 - 3 = 720

14x + 241 - 11 = 720

14x + 230 = 720

14x = 720 - 230

14x = 490

x = 490/14

x = 35

The expression for the angle m∠RST from the given bisctor is; 6x - 18

From the given image in the attachment we are given that;

SQ bisects ∠TSR

m ∠RSQ = 3x - 9

Now, since  SQ is a bisector of ∠TSR, we can say that

m∠RST = 2 * m∠RSQ

Thus angle RST is expressed as;

m∠RST = 2(3x - 9)

m∠RST = 6x - 18

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Answer:

Use sine rule.

Explanation:

[tex]\begin{tabular}{|c|c|c|c|} \cline{1-2} \multicolumn{2}{|c|}{\bf {SOH CAH TOA Formula's}} \\ \cline{1-2} \cline{1-2} \rm{sine rule} & sin(\theta) \sf = opposite/hypotenuse \\ \cline{1-2} \rm{cosine rule} & cos(\theta) \sf = adjacent/hypotenuse \\\cline{1-2} \rm{tan rule} & tan(\theta) \sf = opposite/adjacent \\ \cline{1-2}\end{tabular}[/tex]

If opposite side of an angle and hypotenuse is given.

Use sine rule: sin(θ) = opposite/hypotenuse

For example:

Given that opposite of the angle is 10 cm and hypotenuse is 20 cm.

To find the angle:

sin(θ) = 10/20

θ = sin⁻¹(10/20)

θ = sin⁻¹(1/2)

θ =  30°

Several ways

You can use sin directly

As

Then you can find Ø from it

Otherwise

You may find adjacent using Pythagorean theorem

Then you can use cos

You may use tan even

Answer: 89.7

Step-by-step explanation:

The mean of a data set is the average of all the information given. Therefore, the total combined score is the number of students multiplied by the mean

The total score of the first 44 students: 96.6*44 = 4250.4

The total score of the later 13 students: 66.3*13 = 861.9

(4250.4 + 861.9)/(44 + 13) = 89.7

Hope this helped

Answer:

[tex]f^{-1}(x)=x^2+1[/tex]

Step-by-step explanation:

The inverse of a function is when the x and y are swapped. So the first step is to write f(x) as y and then swap the x and y

Original Equation:

[tex]f(x)=\sqrt{x-1}\\[/tex]

write f(x) as y (since that's what it represents)

[tex]y=\sqrt{x-1}[/tex]

Swap x and y

[tex]x=\sqrt{y-1}[/tex]

Square both sides

[tex]x^2=y-1[/tex]

Add 1 to both sides

[tex]x^2+1=y[/tex]

So this gives you the equation:

[tex]f^{-1}(x)=x^2+1[/tex]

Answer:

vertical shift is 3 units down

horizontal shift is 2 units left

Step-by-step explanation:

y=srx+2-3

vertical shift is 3 units down

horizontal shift is 2 units left

The number of problems Shelly has to complete is 25 problems

x = 10 + 2/7x

x - 2/7x = 10

(7x-2x)/7 = 10

5/7x = 10

x = 10 ÷ 5/7

= 10 × 7/5

= 70/5

x = 35 problems

So,

Number of problems to complete = Total problems - completed problem

= 35 - 10

= 25 problems

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Answer:

90.000 m³

Step-by-step explanation:

V = L × W × H

V = 6 × 5 × 3.000

V = 30 × 3.000

V = 90.000 m³

Hello !

[tex]6 \times 5 \times 3 = 90 {m}^{3} [/tex]

The amount of air is 90m³.

Have a nice day ;)

Answer: 1/9

Step-by-step explanation:

-(8/24)^2 / -(8/24)^0

cancel the negatives and simplify 8/24 to 1/3

(1/3)^2 / (1/3)^0

(1/3)^0 = 1

so,

(1/3)^2 = 1/9

The total cost for the increment is $13,000.

There are 5 employee's in Sasha's department. The total amount of increment is $5000. (5 x $1000).

The lowest salary is 32,000. If it is increased to $40,000. The total cost of the increment is $8000 (40,000 - 32,000)

Total cost of the increment = $8000 + $5000 = $13,000

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The probability that the sample proportion is less than 0.80 is mathematically given as P(z<-0.52)

Generally, the equation for probability is  mathematically given as

p=82/100

Therefore

p=0.82

q=1-p

q=1-0.82

q=0.18

[tex]SE=\sqrt{\frac{p(1-p)}{n}}\\\\SE=\sqrt{\frac{0.8(1-0.8)}{100}}\\\\SE=0.03841[/tex]

b)

[tex]P(p < 0.80)=p(\frac{p-0.82}{0.0384} < \frac{0.8-0.82}{0.0384})\\\\P(z < -0.52)[/tex]

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