Find the mean of this set of data: (2, 5, 3, 9, 7)a. 3.5b. 4c. 5.2d. 5 ! you all in

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?