Finding the Fourth Proportional to 21,013.05, 29,002.95 and 13,061.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,013.05 : 29,002.95 = 13,061.28 : x
2. Step 2: Convert to fraction form
   21,013.05/29,002.95 = 13,061.28/x
3. Step 3: Cross multiply
   21,013.05x = 29,002.95 × 13,061.28
4. Step 4: Simplify right side
   21,013.05x = 378,815,650.78
5. Step 5: Solve for x
   x = 378,815,650.78/21,013.05
6. Step 6: Final answer
   x = 18,027.64