Answer:
It is less than the ideal mechanical advantage
Explanation:
Hi, the actual mechanical advange is less than the ideal. This happens because when making calculations and designs of a machine, the scientist or engineer makes a lot of suppositions that doesn't always reflect the reality perfectly.
That difference between the suppositions and the reality is shown in the difference between the actual mechanical advantage and the ideal.
The porcentual difference between this two is what is called the efficiency