Answer:
248 lbs
Explanation:
Gary's weight after the first week 253 lbs - 4 lbs = 249 lbs
Gary's weight after the second week 249 lbs - 3.5 lbs = 245.5 lbs
Gary's weight after the third week 245.5 lbs - 2 lbs = 243.5 lbs
Gary's weight after the fourth week 243.5 lbs + 4.5 lbs = 248 lbs