Final answer:
Jacob works 384 hours each year.
Step-by-step explanation:
Jacob works 8 hour shifts each weekend. There are 52 weekends in a year, so Jacob works a total of 8 * 52 = 416 hours on the weekends. However, Jacob also takes off four weeks during the year, which means he does not work for 4 * 8 = 32 hours. Therefore, Jacob works a total of 416 - 32 = 384 hours each year.