Finding the Fourth Proportional to 21,570.66, 29,766.33 and 12,139.83

Step by Step Solution

1. Step 1: Write the proportion equation
   21,570.66 : 29,766.33 = 12,139.83 : x
2. Step 2: Convert to fraction form
   21,570.66/29,766.33 = 12,139.83/x
3. Step 3: Cross multiply
   21,570.66x = 29,766.33 × 12,139.83
4. Step 4: Simplify right side
   21,570.66x = 361,358,185.92
5. Step 5: Solve for x
   x = 361,358,185.92/21,570.66
6. Step 6: Final answer
   x = 16,752.30