Two-Sample Difference in Means

Compute the observed difference between the means of two samples, $\bar{a}-\bar{b}\backslash bar\; a-\backslash bar\; b$. The samples may have different lengths.

Implement solve(a, b).

Returns. Return the difference as a Python float (positive when a has the larger mean).

Examples

Example 1

Input:

solve([5.0, 6.0, 7.0], [1.0, 2.0, 3.0])

Output:

4.0

Example 2

Input:

solve([1.0, 2.0], [3.0, 4.0, 5.0, 6.0])

Output:

-3.0