input: Write a python function to compute the total cost given the price, quantity, shipping, and tax.
  assert compute_total_cost(10, 2, 5, 1) == 26
  assert compute_total_cost(15, 3, 10, 2) == 57
  assert compute_total_cost(7.5, 4, 3, 0.5) == 33.5
output: def compute_total_cost(price, quantity, shipping, tax):
      return (price * quantity) + shipping + tax