Finding the Fourth Proportional to 21,648.15, 29,878.89 and 12,700.35

Step by Step Solution

1. Step 1: Write the proportion equation
   21,648.15 : 29,878.89 = 12,700.35 : x
2. Step 2: Convert to fraction form
   21,648.15/29,878.89 = 12,700.35/x
3. Step 3: Cross multiply
   21,648.15x = 29,878.89 × 12,700.35
4. Step 4: Simplify right side
   21,648.15x = 379,472,360.61
5. Step 5: Solve for x
   x = 379,472,360.61/21,648.15
6. Step 6: Final answer
   x = 17,529.09