Finding the Fourth Proportional to 9,105.12, 13,647.60 and 3,909.60

Step by Step Solution

1. Step 1: Write the proportion equation
   9,105.12 : 13,647.60 = 3,909.60 : x
2. Step 2: Convert to fraction form
   9,105.12/13,647.60 = 3,909.60/x
3. Step 3: Cross multiply
   9,105.12x = 13,647.60 × 3,909.60
4. Step 4: Simplify right side
   9,105.12x = 53,356,656.96
5. Step 5: Solve for x
   x = 53,356,656.96/9,105.12
6. Step 6: Final answer
   x = 5,860.07