For this case we can make the following rule of three:
1 box -------------> 15 paperweights
x -------------------> 1269 paperweights
We clear the value of x.
We have then:
x = (1269/15) * (1)
x = 84.6
Rounding to the nearest whole:
x = 85
Answer:
There will be needed about:
x = 85 boxes