Two classmates are preparing research papers and are organizing their information on index cards.

Keiko is using 3 in. x 5 in. cards.

William is using 4 in. x 6 in. cards.

A. Set up a proportion to determine if the students are using index cards that are similar. Are they similar?

B. A third student, Joel, is writing his information on paper that measures 12 in. x 8 in.

Is this similar to either Keiko's or William's cards? Show your setup and work to support your answer.