Question

A set of a thousand numbers has a mean of zero.
All but two of the numbers are 1
What is the mean of the other two numbers?

Answer 1

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:

$M = \frac{x_1 + x_2 + ... + x_n}{N}$

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:

$\frac{1 + 1 + 1 + ... A + B}{1000} = 0$

We can rewrite this as:

$1 + 1 + 1 +... + A + B = 0$

And we have 998 ones, then:

$1 + 1 + 1 +... + A + B = 998 + A + B = 0\\\\B = - 998 - A$

Now we have B isolated.

With this, the mean of A and B can be written as:

$\frac{A + B}{2} = \frac{A - 980 - A}{2} = -490$

So we can conclude that the mean of the other two numbers is -490.

If you want to learn more, you can read:

https://brainly.com/question/22871228