A local sandwich shop makes an Italian sandwich that contains ham, salami, and pepperoni meats. Let X represent the weight of ham, Y represent the weight of salami, and Z represent the weight of pepperoni for each Italian sandwich made. The mean of X is 2 ounces, the mean of Y is 1.25 ounces, and the mean of Z is 1.75 ounces. What is the mean of the sum, S = X + Y + Z?