Answer:
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
Step-by-step explanation:
First of all, let us have a look at the steps of finding inverse of a function.
1. Replace y with x and x with y.
2. Solve for y.
3. Replace y with 
Given that:

Now, let us find inverse of each option one by one.
I. y = x, a(x) = x
Replacing y with and x with y:
x = y
x =
=
Hence, I is true.
II. 
Replacing y with and x with y:

=
Hence, II is true.
III. 
Replacing y with and x with y:
Hence, III is not true.
IV. 
Replacing y with and x with y:
Hence, IV is not true.
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
The percent of students that are aged 19 years or more is determined as 84%.
<h3>One standard deviation below the mean</h3>
In a normal distribution curve 1 standard deviation below the mean is defined as follows;
- 1 std below mean : M - d = 16%
M - d = 20.6 yrs - 1.3 yrs = 19.3 years ≈ 19 years
19 years or more will occur at (M - d) + (M) + (M + 2d) = 100% - (M - d)
= 100% - 16%
= 84%
Thus, the percent of students that are aged 19 years or more is determined as 84%.
Learn more about normal distribution here: brainly.com/question/4079902
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Answer:

Now we can find the second central moment with this formula:

And replacing we got:

And the variance is given by:
![Var(X) = E(X^2) - [E(X)]^2](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20-%20%5BE%28X%29%5D%5E2)
And replacing we got:

And finally the deviation would be:

Step-by-step explanation:
We can define the random variable of interest X as the return from a stock and we know the following conditions:
represent the result if the economy improves
represent the result if we have a recession
We want to find the standard deviation for the returns on the stock. We need to begin finding the mean with this formula:

And replacing the data given we got:

Now we can find the second central moment with this formula:

And replacing we got:

And the variance is given by:
![Var(X) = E(X^2) - [E(X)]^2](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20-%20%5BE%28X%29%5D%5E2)
And replacing we got:

And finally the deviation would be:

Answer:
(4x^(2)-7x+11)/(5x^(2)-3x+2)
Step-by-step explanation: