Finding the Fourth Proportional to 11,887.72, 16,407.78 and 7,909

Step by Step Solution

1. Step 1: Write the proportion equation
   11,887.72 : 16,407.78 = 7,909 : x
2. Step 2: Convert to fraction form
   11,887.72/16,407.78 = 7,909/x
3. Step 3: Cross multiply
   11,887.72x = 16,407.78 × 7,909
4. Step 4: Simplify right side
   11,887.72x = 129,769,132.02
5. Step 5: Solve for x
   x = 129,769,132.02/11,887.72
6. Step 6: Final answer
   x = 10,916.23