Finding the Fourth Proportional to 21,790.52, 32,603.28 and 12,910.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,790.52 : 32,603.28 = 12,910.61 : x
2. Step 2: Convert to fraction form
   21,790.52/32,603.28 = 12,910.61/x
3. Step 3: Cross multiply
   21,790.52x = 32,603.28 × 12,910.61
4. Step 4: Simplify right side
   21,790.52x = 420,928,082.50
5. Step 5: Solve for x
   x = 420,928,082.50/21,790.52
6. Step 6: Final answer
   x = 19,317.03