Finding the Fourth Proportional to 9,860.88, 13,608.57 and 5,385.05

Step by Step Solution

1. Step 1: Write the proportion equation
   9,860.88 : 13,608.57 = 5,385.05 : x
2. Step 2: Convert to fraction form
   9,860.88/13,608.57 = 5,385.05/x
3. Step 3: Cross multiply
   9,860.88x = 13,608.57 × 5,385.05
4. Step 4: Simplify right side
   9,860.88x = 73,282,829.88
5. Step 5: Solve for x
   x = 73,282,829.88/9,860.88
6. Step 6: Final answer
   x = 7,431.67