An automated process is used to fill bags with fertilizer

An automated process is used to fill bags with fertilizer. The weight of the bags is a random variable with a normal distribution having a mean μ=50 pounds and variance= 4.5. Two bags are selected independently and at random and loaded onto a pallet for shipping. If the total weight of the two bags, X1 + X2 exceeds 105.4 pounds, a surcharge is added onto the shipping cost. What percentage of all shipments can be expected to result in a surcharge being added to the shipping cost?