Boys to girls is 4:5.......added = 9
so 4/9 are boys and 5/9 are girls
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:
17, 19, 21
Step-by-step explanation:
If we denote the smallest number as x, then the middle number will be x + 2 and the largest number will be x + 2 + 2.
The equation is:
x + (x + 2) = 3 * (x + 2 + 2) - 27
2x + 2 = 3x + 12 - 27
2x - 3x = 12 - 27 - 2
-x = -17
x = 17
The numbers are: 17, 19, 21
Let's check to be sure:
17 + 19 = 36
3 * 21 - 27 = 63 - 27 = 36
Step-by-step explanation:
5x-16 = 3 (10+x)
=> x= 23
Answer:
answer A and B are the same there just the opposite of each other. so A or B would work.
Step-by-step explanation:
95×(12) +225×(12)