The mechanical advantage (MA) can be calculated using the formula:
\[ \text{Mechanical Advantage} (MA) = \frac{\text{Load Force}}{\text{Effort Force}} \]
In this case, the load force is 180 N (the force exerted on the load by the lever) and the effort force is 40.0 N (the force applied to the lever). Plugging in these values:
\[ MA = \frac{180 , \text{N}}{40.0 , \text{N}} = 4.5 \]
Therefore, the mechanical advantage of the lever is 4.5.