Arranging x numbers in y groups with an approximate sum of z

I have ''x'' set of numbers (say { 1.3, 2.7, 3.8, 1.9, 8.2, 1.5, 18.4, 22, 5.3}) which I want to group in ''y'' (say 3) sets with each set totaling to an approximate value of ''z'' (say 7).

How can i do this using excel?