Finding the Fourth Proportional to 15,478.30, 21,359.70 and 8,404.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,478.30 : 21,359.70 = 8,404.72 : x
2. Step 2: Convert to fraction form
   15,478.30/21,359.70 = 8,404.72/x
3. Step 3: Cross multiply
   15,478.30x = 21,359.70 × 8,404.72
4. Step 4: Simplify right side
   15,478.30x = 179,522,297.78
5. Step 5: Solve for x
   x = 179,522,297.78/15,478.30
6. Step 6: Final answer
   x = 11,598.32