David Elkington, the Chief Executive Officer (CEO) of InsideSales.com, wondered whether the cycles of the moon affect sales. He got the idea from his father-in-law, who said that emergency rooms are crowded when the moon is full. There are eight phases of the moon: New Moon, Waning Crescent, Third Quarter, Waning Gibbous, Full, Waxing Gibbous, First Quarter, and Waxing Crescent. Explain how to obtain and analyze data to determine whether moon cycles affect sales.