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2 years ago

Can you no come in to this question we dont know you.

Mathematics

2 answers:

xeze [42]2 years ago

8 0

Answer:

yes

Step-by-step explanation:

crimeas [40]2 years ago

7 0

Answer:

Step-by-step explanation:

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Let

Digiron [165]

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

From the given second moment and variance, we find the expectation of $X$ :

$V(X) = E(X^2) - E(X)^2 \implies E(X) = \sqrt{E(X^2) - V(X)} = \sqrt{23}$

Expectation is linear, so

$E(Y) = E(2X+10) = 2 E(X) + 10 = \boxed{2\sqrt{23} + 10}$

Using the same variance identity, we have

$V(Y) = V(2X+10) = E((2X+10)^2) - E(2X+10)^2$

and

$E((2X+10)^2) = E(4X^2 + 40X + 100) = 4E(X^2) + 40E(X) + 100 = 424 + 40\sqrt{23}$

so that

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

Alternatively, we can use the identity

$V(aX+b) = a^2 V(X) \implies V(2X+10) = 4V(X) = 232$

5 0

2 years ago

Find the value of x.

vredina [299]

Answer:

Step-by-step explanation:

8 0

2 years ago

What is the area of a circle with a radius of 7 inches

Fynjy0 [20]

Area formula is A=πr2
A=3.1416(radius)2 (radius is 7)
A=3.1416(49)
A=153.94
The area is 153.94 inches.
Hope that was helpful :)

7 0

2 years ago

Read 2 more answers

What would the answer be for this equation 7x/20 - 5x/12

polet [3.4K]

Answer:

$\frac{1}{15} x$

Step-by-step explanation:

$\frac{7x}{20} - \frac{5x}{12}$

$\frac{3 \times 7x}{3 \times 20} - \frac{5 \times 5x}{5 \times 12}$

$\frac{21x}{60} - \frac{25x}{60}$

$\frac{21x - 25x}{60} = (21 - 25)x = - 4x$

$\frac{ - 4x}{60} = - \frac{ x}{15}$

$\boxed{\green{= \frac{1}{15} x}}$

4 0

2 years ago

Rewrite the following equations in the form y=mx + b and identify the values of m and b

arlik [135]

You need to put the equations?

5 0

2 years ago