Finding the Fourth Proportional to 21,614.71, 29,830.71 and 12,669.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,614.71 : 29,830.71 = 12,669.78 : x
2. Step 2: Convert to fraction form
   21,614.71/29,830.71 = 12,669.78/x
3. Step 3: Cross multiply
   21,614.71x = 29,830.71 × 12,669.78
4. Step 4: Simplify right side
   21,614.71x = 377,948,532.94
5. Step 5: Solve for x
   x = 377,948,532.94/21,614.71
6. Step 6: Final answer
   x = 17,485.71