Finding the Fourth Proportional to 9,908.31, 13,672.67 and 5,715.75

Step by Step Solution

1. Step 1: Write the proportion equation
   9,908.31 : 13,672.67 = 5,715.75 : x
2. Step 2: Convert to fraction form
   9,908.31/13,672.67 = 5,715.75/x
3. Step 3: Cross multiply
   9,908.31x = 13,672.67 × 5,715.75
4. Step 4: Simplify right side
   9,908.31x = 78,149,563.55
5. Step 5: Solve for x
   x = 78,149,563.55/9,908.31
6. Step 6: Final answer
   x = 7,887.27