Finding the Fourth Proportional to 10,913.60, 16,348.84 and 8,561.89

Step by Step Solution

1. Step 1: Write the proportion equation
   10,913.60 : 16,348.84 = 8,561.89 : x
2. Step 2: Convert to fraction form
   10,913.60/16,348.84 = 8,561.89/x
3. Step 3: Cross multiply
   10,913.60x = 16,348.84 × 8,561.89
4. Step 4: Simplify right side
   10,913.60x = 139,976,969.71
5. Step 5: Solve for x
   x = 139,976,969.71/10,913.60
6. Step 6: Final answer
   x = 12,825.92