Can someone help me on this

What situation is an example of an observational study

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package