Finding the Fourth Proportional to 15,456.28, 21,329.56 and 8,382.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,456.28 : 21,329.56 = 8,382.72 : x
2. Step 2: Convert to fraction form
   15,456.28/21,329.56 = 8,382.72/x
3. Step 3: Cross multiply
   15,456.28x = 21,329.56 × 8,382.72
4. Step 4: Simplify right side
   15,456.28x = 178,799,729.20
5. Step 5: Solve for x
   x = 178,799,729.20/15,456.28
6. Step 6: Final answer
   x = 11,568.10