Afox a coyote and a wolf weigh a total of 120 pounds the ratio of the weight of fox to the weight of coyote is 3: 8 the weight of the coyote is 32 pound what is the weight of the wolf

There is not enough information to calculate this. 

Knowing the weight ratio of the fox to coyote as 3:8 in no way allows you to know the respective ratio of the wolf. To know the weight of the wolf would require knowing its ratio value, then the weights of all 3 is an easy calculation. 
Example - 3:8:15 (f:c:w) is a plausible ratio based upon real-world weight averages for certain species/subspecies of the three. 
- knowing the values of the 3 terms as 3:8:15 gives a total of 3+8+15 = 26 ratio values 
- you then simply divide the total weight by this ratio value total; 120/26 = 4.62 
- so each ratio value is 4.62 units of weight*** 
- now, simply calculate the weight of each canid by multiplying its ratio value by the unit of weight... 
fox; 3 x 4.62 = 13.86 
coyote; 8 x 4.62 = 36.96 
wolf; 15 x 4.62 = 69.3 
Validate the ratios by adding the weights together (we should get 120) 13.86 + 36.96 + 69.3 = 120.12 
The total is slightly out because that 4.62 figure was a rounding up. 

Now, the thing is, there is nothing given that allows us to know exactly what ratio value the wolf should be, I chose 15 myself because that is a real-world plausible value when compared to 3:8 for the other 2. Changing it to 16, say, means that there are now 27 ratio values total giving a ratio value of 120/27 = 4.44 obviously changing the weights of all 3.