Find the next term in the sequence
simplify complete
3 1/4, 3 3/8, 3 1/2, 3 5/8, [? ] [? ]/[? ]

This is an arithmetic sequence because each term is 1/8 more than the previous term.  This is called the common difference and it is what defines an arithmetic sequence.

a(n)=a+d(n-1), where a is 1st term, d is common difference, and n it term #

In this case:

a(n)=3.25+0.125(n-1) or more neatly...

a(n)=3.125+0.125n

a(5)=3.75