Finding the Fourth Proportional to 21,012.50, 29,007.77 and 13,057.29

Step by Step Solution

1. Step 1: Write the proportion equation
   21,012.50 : 29,007.77 = 13,057.29 : x
2. Step 2: Convert to fraction form
   21,012.50/29,007.77 = 13,057.29/x
3. Step 3: Cross multiply
   21,012.50x = 29,007.77 × 13,057.29
4. Step 4: Simplify right side
   21,012.50x = 378,762,799.86
5. Step 5: Solve for x
   x = 378,762,799.86/21,012.50
6. Step 6: Final answer
   x = 18,025.60