PLEASE HELP i can't figure it out what does this mean??

Which of the following would represent the sum of 3 consecutive integers if x is the first integer?

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.

What is the difference between the predicted value and the actual value