Find the geometric mean between 4 and 25

Need on this geometry question. explain how you did it.

15 and 14.7 are 1 apart, so 15 – 14.7 must be 1.

Jalen charges $25.50 for every 3 hours of yard work he does for his neighbors. ralph charges $34 for every 4 hours of work that he does. who charges less? opinions: 1.they charge the same amount 2.jalen 3.ralph