Mary Beth is thinking of marketing a new energy drink. Her target market will be parents of young children who need an energy boost in the car while driving from school to sport games. She plans on testing whether or not parents will buy her new energy drink by offering free samples to the first 100 parents leaving Trade Joe's at Stonestown. If the majority of the parents say they will buy her product, she will go ahead with the product launch. Mary Beth may have a problem with the ___________ of her findings in this market research project