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boyakko [2]
2 years ago
13

The random variable X has mean 12 and standard deviation 3. The random variable W is defined as W=7+2X . What are the mean and s

tandard deviation of W ?
Mathematics
2 answers:
patriot [66]2 years ago
6 0

Answer:

The mean and standard devaition of W are 6 and 31 respectively.

Step-by-step explanation:

Given that:

W = 7 + 2X

Variance (W) = Variance(7 + 2X)

For a term constant term, the variance is zero.

So;

W = Var (2X)

W = 4 × Var(X)

W = 4 × (SD (X))²

W = 4 × (3)²

W = 4 × 9

W = 36

Thus, Variance (W) = 36

The standard deviation of W = \sqrt{variance}

W = \sqrt{36}

W = 6

Also;

E(W) = E(7 +2 X)

E(W) = 7 + 2 × E(X)

where;

mean X = 12

E(W) = 7 + 2(12)

E(W) = 31

Thus, the mean and standard devaition of W are 6 and 31 respectively.

Ivan2 years ago
4 0

Answer:

The mean is 31, and the standard deviation is 6.

Step-by-step explanation:

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What's one way to check the answer to 5×6=30
Alla [95]

Step-by-step explanation:

30÷6 =5 or 30÷5 =6 good luck!

7 0
2 years ago
Let f(x)=3x-6 and g(x)=x-2 find f(g(5))-ie. (f • g)(5) and its domain
Molodets [167]

Solution for f(g(5)):


The notation f(g(5)) or (f • g)(5) means that we first plug 5 into the function g(x), simplify, then plug the answer that we got to f(x). We will do this step-by-step:


Step 1: Plugging 5 to g(x)

g(5)=5-2=3


Step 2: Plugging the answer to f(x)

f(3)=3(3)-6=9-6=3


ANSWER: f(g(5)) is equal to 3.


Domain:


For the function f(g(x)), we can find the domain by analyzing the domains of each individual functions separately and excluding certain values depending on the restrictions from the outermost function.


However, since both functions have all real numbers as its domain, we will not need to do any exclusion anymore.


ANSWER: The domain of the function is all real numbers.

3 0
3 years ago
What is 36:12 as a fraction in lowest terms?
Rom4ik [11]
Did you mean 36/12? If so the answer would be 3/1 or 3.
3 0
3 years ago
Which of the ordered pairs is a solution of the following equation <br> 5x-2y=20
Anastasy [175]

Answer:

Step-by-step explanation:

5x + 2y = 20

Here we will show you how to calculate the following:

Calculate and show the solution for the x-intercept and y-intercept of 5x + 2y = 20.

Calculate the graph plot coordinates for 5x + 2y = 20

Solve 5x + 2y = 20 for x and also for y.

Calculate and show the solution for the slope of 5x + 2y = 20

Find x-intercept

The x-intercept is where the graph crosses the x-axis. To find the x-intercept, we set y1=0 and then solve for x.

5x + 2y = 20

5x + 2(0) = 20

x1 = 4    y1 = 0

Find y-intercept

The y-intercept is where the graph crosses the y-axis. To find the y-intercept, we set x2=0 and then solve for y.

5x + 2y = 20

5(0) + 2y = 20

y2 = 10    x2 = 0

 

Get Graph Plot Coordinates

Getting two graph points will allow you to make a straight line on a graph. The plot coordinate format is (x1,y1) and (x2,y2).

Thus, we use the x-intercept and y-intercept results above to get the graph plots for 5x + 2y = 20 as follows:

(x1,y1) and (x2,y2)

(4,0) and (0,10)

Find slope

The slope of the line (m) is the steepness of the line. It is the change in the y coordinate divided by the corresponding change in the x coordinate. Simply plug in the coordinates from above and solve for m to get the slope for 5x + 2y = 20

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

m = (10 - 0)/(0 - 4)

m = -2.5

3 0
3 years ago
Are the two right triangles trs and wuv congruent? If so name the congruence postulate that applies
Nataly_w [17]
<span>Two figures are said to be congruent when they have the same shape and size or if one object is a mirror image of the other object.<span> The right triangles trs and wuv are congruent when they have equal lengths of the sides and having equal sides, angles should as well be equal with the two triangles.</span></span>
8 0
3 years ago
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