Answer:
264 ounces
Step-by-step explanation:
#Convert Xan weight into ounces:

Convert Katie's 88 pounds 11 ounce to ounces:

The difference is calculated by subtracting Xan's from Katie's:

Hence, the difference between the weights is 264 ounces
4x/15 = 60/x
4x^2 = 900
x^2 = 225
x = 15