Finding the Fourth Proportional to 9,901.56, 13,664.16 and 5,425.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,901.56 : 13,664.16 = 5,425.20 : x
2. Step 2: Convert to fraction form
   9,901.56/13,664.16 = 5,425.20/x
3. Step 3: Cross multiply
   9,901.56x = 13,664.16 × 5,425.20
4. Step 4: Simplify right side
   9,901.56x = 74,130,800.83
5. Step 5: Solve for x
   x = 74,130,800.83/9,901.56
6. Step 6: Final answer
   x = 7,486.78