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:
![M = \frac{x_1 + x_2 + ... + x_n}{N}](https://tex.z-dn.net/?f=M%20%3D%20%5Cfrac%7Bx_1%20%2B%20x_2%20%2B%20...%20%2B%20x_n%7D%7BN%7D)
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:
![\frac{1 + 1 + 1 + ... A + B}{1000} = 0](https://tex.z-dn.net/?f=%5Cfrac%7B1%20%2B%201%20%2B%201%20%2B%20...%20A%20%2B%20B%7D%7B1000%7D%20%20%3D%200)
We can rewrite this as:
![1 + 1 + 1 +... + A + B = 0](https://tex.z-dn.net/?f=1%20%2B%201%20%2B%201%20%2B...%20%2B%20A%20%2B%20B%20%3D%200)
And we have 998 ones, then:
![1 + 1 + 1 +... + A + B = 998 + A + B = 0\\\\B = - 998 - A](https://tex.z-dn.net/?f=1%20%2B%201%20%2B%201%20%2B...%20%2B%20A%20%2B%20B%20%3D%20998%20%2B%20A%20%2B%20B%20%3D%200%5C%5C%5C%5CB%20%3D%20-%20998%20-%20A)
Now we have B isolated.
With this, the mean of A and B can be written as:
![\frac{A + B}{2} = \frac{A - 980 - A}{2} = -490](https://tex.z-dn.net/?f=%5Cfrac%7BA%20%2B%20B%7D%7B2%7D%20%20%3D%20%5Cfrac%7BA%20-%20980%20-%20A%7D%7B2%7D%20%3D%20-490)
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:
Using the equation y = abx , substitute both of your given points into that equation.
2 = ab2 and 4 = ab3 Solve each equation for a.
2⁄b2 and 4⁄b3 = a Therefore, 2⁄b2 = 4⁄b3
Cross multiply: 2b3 = 4b2 Divide both sides by b2
2b = 4 a = 2/4 = 1/2
b = 2
y = 1 (2)x
2
Step-by-step explanation:
1) y = 1x + 95.50
x = number of bandanas
2) y = (1 • 50) + 95.50
$145.50 for 50 bandannas
3) 116.50 = 1x + 95.50
get x by itself
116.50 = 1x+ 95.50
-95.50 -95.50
21 = 1x
divide by 1
21 = x
you get 21 bandannas when you pay $116.50
The two horizontal lines are parallel ( This is given by the red triangles)
Because the lines are parallel, the two angles 1 & 2 would be the same.
Set the two equations for the angle to equal each other and solve:
8y-6 = 7y
Add 6 to each side:
8y = 7y+6
Subtract 7y from each side:
y = 6
Now you have the value for y, solve for angle 2 by replacing y with 6:
Angle 2 = 7y = 7(6) = 42 degrees.
The answer is 75! Explanation: Use the distance formula:)