Write a function, running_total(), that takes a tuple, numbers, as an argument and returns a tuple with the running totals of the numbers. Example runs: >>> seq = (1, 2, 4, 6) >>> running_total(seq) # it calculates (1, 1+2, 1+2+4, 1+2+4+6) and will return: (1, 3, 7, 13)