Finding the Fourth Proportional to 10,609.40, 14,644.92 and 9,111.30

Step by Step Solution

1. Step 1: Write the proportion equation
   10,609.40 : 14,644.92 = 9,111.30 : x
2. Step 2: Convert to fraction form
   10,609.40/14,644.92 = 9,111.30/x
3. Step 3: Cross multiply
   10,609.40x = 14,644.92 × 9,111.30
4. Step 4: Simplify right side
   10,609.40x = 133,434,259.60
5. Step 5: Solve for x
   x = 133,434,259.60/10,609.40
6. Step 6: Final answer
   x = 12,576.99