Studies in the field of psychology have concluded that first-born children in a family are more likely to be great achievers in their studies than their younger brothers and sisters. A school psychologist wants to assess whether the grades and the IQ (intelligence quotient) differ markedly between students who are first-born in their family and other students. She compiles the following data:

(a) Compute the mean and the median of the grades and of the IQs for the two groups of students.

(b) Is the difference between the two groups large enough in your opinion?

(We will see later in the manual that there is a rigorous way of answering this question.)

(c) Is the mode useful for this discussion? Explain why.