Let's start by cleaning the data a little. This dataset has several measurements taken where the helicopter hit the stairwell, a nearby building, or some other obstruction that impacted the fall time. These results should be discarded since they wouldn't be an accurate reflection of what we're trying to measure.

Create a new table called helicopters that only contains the rows of copters that correspond to a helicopter that did not hit an obstruction during the fall.

Suppose you're interested in determining how the rotor length might impact fall time. Start by creating a histogram that displays the distribution of times for helicopters with long rotors. Use the provided bins stored to my_bins.