An ice chest at a beach party contains 15 cans of soda at 3 ° C. Each can of soda has a mass of 0.38 kg and a specific heat capacity of 4000 J/(kg · C °). Someone adds a 6.2-kg watermelon at 25 ° C to the chest. The specific heat capacity of watermelon is nearly the same as that of water. Ignore the specific heat capacity of the chest and determine the final temperature T of the soda and watermelon.