We want to find the mean of two elements in a set, given that we know the other elements of the set and the mean of the whole set.
The answer is: -490
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For a set with N elements {x₁, x₂, ..., xₙ} the mean is given by:

Here we know that:
- The mean of the set is 0.
- The set has 1000 elements.
- 998 of these elements are ones, the other two are A and B.
We want to find the mean of the values of A and B.
First, we can start by writing the equation for the mean:

We can rewrite this as:

And we have 998 ones, then:

Now we have B isolated.
With this, the mean of A and B can be written as:

So we can conclude that the mean of the other two numbers is -490.
If you want to learn more, you can read:
brainly.com/question/22871228
Answer:
answer C
Hyperbolic geometry
The sum of the angles of a hyperbolic triangle is less than 180°.
Answer
-11/3>x>7/3
Step-by-step explanation:
|3*7/3+2|=9
|7+2|=9
|9|=9
9=9
therefore, x must be > 7/3
|3*-11/3+2|=9
|-11+2|=9
|-9|=9
9=9
therefore, x must be < -11/3
The ray or line is called Bisector