Finding the Fourth Proportional to 10,915.10, 16,409.10 and 9,311.30

Step by Step Solution

1. Step 1: Write the proportion equation
   10,915.10 : 16,409.10 = 9,311.30 : x
2. Step 2: Convert to fraction form
   10,915.10/16,409.10 = 9,311.30/x
3. Step 3: Cross multiply
   10,915.10x = 16,409.10 × 9,311.30
4. Step 4: Simplify right side
   10,915.10x = 152,790,052.83
5. Step 5: Solve for x
   x = 152,790,052.83/10,915.10
6. Step 6: Final answer
   x = 13,998.04