1 March, 08:14

# Suppose that you need to create a list of n values that have a specific known mean. Some of the n values can be freely selected. How many of the n values can be freely assigned before the remaining values are determined

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1. 1 March, 08:30
0
Answer: a maximum of n-1 can be freely selected

Step-by-step explanation:

The fact that we already know the mean means that, if we have n values:

X = (x₁ + x₂ + ... + xₙ) / n

where X is known and n is known.

Now, suppose we can assign n freely therms: this is not the case, because if X is different than 0, we could assign the n values equal to zero and the equality would be false.

Now suppose we can assign n-1 values freely, then we would have the equation:

X = (x₁ + x₂ + ...) / n + xₙ/n

where the term (x₁ + x₂ + ...) is conformed with the random values and xₙ must be chosen in order to satisfy the equation. So we would have the equation:

(X - (x₁ + x₂ + ...) / n) * n = n*X - (x₁ + x₂ + ...) = xₙ

The equation that can be solved, so a maximum of n-1 can be freely selected.
2. 1 March, 08:35
0
n-1

Step-by-step explanation:

All but one of the values may be freely chosen. The last one must be chosen to bring the sum to the a value that is n times the mean.