$$43.5 \text{ g} = 43.5 \times 10^{-3} \text{ kg}$$

Step 2: Calculate the density of the oil using the formula:

$$\text{Density} = \frac{\text{Mass}}{\text{Volume}}$$

Substituting the values we have:

$$\text{Density} = \frac{43.5 \times 10^{-3} \text{ kg}}{50 \times 10^{-3} \text{ L}}$$

Step 3: Simplify the units.

$$\text{Density} = \frac{43.5 \text{ kg}}{50 \text{ L}}$$

Therefore, the density of the cooking oil is 0.87 kg/L.