The question isn't incredibly helpful in telling whether the scale factor stated is a linear one or not; I will give you the answer for if it is and if it isn't:
If it isn't linear:
You can simply multiply the volume of the cone that is given by the S.F and that will be your answer so:
1340 × 1/4 = 335 in³
If the S.F is linear:
You'll simply need to cube the S.F first to make it 'compatible' put simply, so:
(1/4)³ = 1/64
1340 × 1/64 = 20.9375
--> 21 in³ (to the nearest in³)