A ship carrying ice over a lake breaks and spills its cargo.If 3650.0 g of ice at 0.00 celcius are released into the 15456200 g of water in the lake at 17.0 celcius, what will the final temperature be? (heat of fusion=79.0 cal)

and i got the answer of 16.98 but I think it is wrong. How do you solve this problem?

I have the same number you have. You wouldn't expect the temperature to change very much with that much water involved.

By the way, not the correct spelling of celsius. A second by the way is that since we are allowed only 3 significant figures, the 16.98 value should be rounded to 17.0 which is just another way of saying that the amount of change is insignificant.