In Steve's statistics class, the final grade is a weighted mean of homework (which counts for 15% of the grade), three tests grades (which each count for 15% of the grade), and a final exam (which counts for 40% of the final grade). Steve has a 60 on homework. He has tests grades of 75, 70, and 75. He has a 80 on the final exam. What is Steve's final grade?