Finding the Fourth Proportional to 21,314.50, 29,414.20 and 12,816.88

Step by Step Solution

1. Step 1: Write the proportion equation
   21,314.50 : 29,414.20 = 12,816.88 : x
2. Step 2: Convert to fraction form
   21,314.50/29,414.20 = 12,816.88/x
3. Step 3: Cross multiply
   21,314.50x = 29,414.20 × 12,816.88
4. Step 4: Simplify right side
   21,314.50x = 376,998,124.63
5. Step 5: Solve for x
   x = 376,998,124.63/21,314.50
6. Step 6: Final answer
   x = 17,687.41