FIRST YOU FIND THE TOTAL NUMBER OF RIGHT-HANDED BY DOING
5:8 = 45:x
CROSS MULTIPLY : 5x = 45(8)
5x = 360
x = 360/5
x = 72
THE TOTAL NUMBER OF BATTERS = 45 + 72 =117
THE RATIO OF LEFT-HANDED BATTERS TO THE TOTAL NUMBER OF BATTERS IS 45/117 ( YOU CAN SIMPLIFY BOTH BY 9 ); 45/117 = 5/13.
HOPE THIS HELPED