Devon wants to know if drinking milk before bed helps teenagers sleep. he chooses 10 friends on his high school basketball team for his study. every night for one month the friends drink a glass of milk before bed and later record how many hours they sleep that night. Describe three reasons why Devon's study design is flawed.

Three reasons why this design is flawed are that he is only surveying the basketball players. The population sample should include a mix of many teenagers if this is the hypothesis. The second reason this is flawed is that he is only collection data of ten people (whom are his friends), causing possible biased data and not enough evidence with only 10 people. Another flaw is the cup size. How much is each person drinking? Cups come on different sizes, but the amount should be the same for all.