ANSWER and Step-by-step explanation
We want to determine why a person weighs lighter at the equator.
At the equator, an object will weigh slightly less as a result of the slightly greater centripetal force and the slight increase in distance from the center of gravity of the earth due to the equatorial bulge. This would imply a decrease in the gravitational force that an object experiences.
In other words, the earth is not a perfect sphere, and so, at the equator, an object will be slightly farther from the center.
That is the answer.