Chapter 6.5, Problem 62E

Exercises 61-64 Social Networks We can calculate social distance between people using matrices. For example, people you like area social distance of 1 from you. People your friends like are a social distance of 2 from you. A person can be a social distance of 1 and 2 from you if you like them and have a friend who also likes them.

$A=\left[\begin{array}{ccccc}0& 1& 0& 0& 0\\ 1& 0& 0& 0& 0\\ 1& 1& 0& 1& 1\\ 1& 0& 0& 0& 1\\ 1& 0& 0& 1& 0\end{array}\right]$

62. There is a 1 in column 1 row 4 of $A^2$. Interpret this.