Finding the Fourth Proportional to 9,917.56, 13,686.12 and 5,725.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,917.56 : 13,686.12 = 5,725.72 : x
2. Step 2: Convert to fraction form
   9,917.56/13,686.12 = 5,725.72/x
3. Step 3: Cross multiply
   9,917.56x = 13,686.12 × 5,725.72
4. Step 4: Simplify right side
   9,917.56x = 78,362,891.01
5. Step 5: Solve for x
   x = 78,362,891.01/9,917.56
6. Step 6: Final answer
   x = 7,901.43