Answer
There are 0.581 kg of nitrogen in 4.15 kg of fertilizer.
Work Step by Step
There is 14.0% nitrogen ( by mass) in 4.15 kg of fertilizer. This information can be written:
Nitrogen mass ( in 4.15 kg fertilizer) = 14.0% x 4.15 kg
Nitrogen mass ( in 4.15 kg fertilizer) = $\frac{14}{100}$ x 4.15 kg
Nitrogen mass ( in 4.15 kg fertilizer) = 0.581 kg
Therefore there are 0.581 kg of nitrogen in 4.15 kg of fertilizer.