The answer is 3000cm as volume = L*W*H
Answer:
Let fertilizer be F
and peat moss be P
since F is proportional to P
F = kP
where, k = constant of proportionality
k = F/P
putting in the values,
k = (3/4) /12
k = 3/4 * 1/12
k = 1/16
Therefore the constant of proportionality is 1/16.