function subtractFromMean(mean, n, value) {
    return (mean * n - value) / (n - 1);
}
When removing a value from a list, one does not have to necessary
recompute the mean of the list in linear time. They can instead use
this function to compute the new mean by providing the current mean,
the number of elements in the list that produced it and the value to remove.

@since 3.0.0
@param {number} mean current mean
@param {number} n number of items in the list
@param {number} value the value to remove
@returns {number} the new mean

@example
subtractFromMean(20.5, 6, 53); // => 14