Finding the Fourth Proportional to 11,889.36, 16,414.56 and 7,916.40

Step by Step Solution

1. Step 1: Write the proportion equation
   11,889.36 : 16,414.56 = 7,916.40 : x
2. Step 2: Convert to fraction form
   11,889.36/16,414.56 = 7,916.40/x
3. Step 3: Cross multiply
   11,889.36x = 16,414.56 × 7,916.40
4. Step 4: Simplify right side
   11,889.36x = 129,944,222.78
5. Step 5: Solve for x
   x = 129,944,222.78/11,889.36
6. Step 6: Final answer
   x = 10,929.45