Finding the Fourth Proportional to 11,152.31, 15,351.56 and 9,639.18

Step by Step Solution

1. Step 1: Write the proportion equation
   11,152.31 : 15,351.56 = 9,639.18 : x
2. Step 2: Convert to fraction form
   11,152.31/15,351.56 = 9,639.18/x
3. Step 3: Cross multiply
   11,152.31x = 15,351.56 × 9,639.18
4. Step 4: Simplify right side
   11,152.31x = 147,976,325.17
5. Step 5: Solve for x
   x = 147,976,325.17/11,152.31
6. Step 6: Final answer
   x = 13,268.67