The box plot shows the number of years during which 16 schools have participated in a marching band competition: A box plot is titled Years of Participation and labeled Years. Number line from 0 to 10 with primary markings and labels at 0, 5, and 10. The box extends from 3 to 7 on the number line. There is a vertical line at 5. The whiskers end at 1 and 10. At least how many schools have participated for 3 to 7 years? (4 points) 3 schools 5 schools 7 schools 8 schools