11. The weight of large bags of one brand of potato chips is a random variable with a mean of 18 ounces and a standard deviation of 0.7 ounces. The amount of chips a professional caterer pours into a certain size of serving bowl can be described as a random variable with a mean of 4 ounces and a standard deviation of 0.3 ounces. The mean amount left in the bag after the caterer has filled two bowls is 10 ounces. Assuming these two variables are independent, what is the standard deviation of this remaining weight