Finding the Fourth Proportional to 15,429.21, 21,292.46 and 8,355.78

Step by Step Solution

1. Step 1: Write the proportion equation
   15,429.21 : 21,292.46 = 8,355.78 : x
2. Step 2: Convert to fraction form
   15,429.21/21,292.46 = 8,355.78/x
3. Step 3: Cross multiply
   15,429.21x = 21,292.46 × 8,355.78
4. Step 4: Simplify right side
   15,429.21x = 177,915,111.42
5. Step 5: Solve for x
   x = 177,915,111.42/15,429.21
6. Step 6: Final answer
   x = 11,531.06