Finding the Fourth Proportional to 21,570.76, 29,768.61 and 12,139.93

Step by Step Solution

1. Step 1: Write the proportion equation
   21,570.76 : 29,768.61 = 12,139.93 : x
2. Step 2: Convert to fraction form
   21,570.76/29,768.61 = 12,139.93/x
3. Step 3: Cross multiply
   21,570.76x = 29,768.61 × 12,139.93
4. Step 4: Simplify right side
   21,570.76x = 361,388,841.60
5. Step 5: Solve for x
   x = 361,388,841.60/21,570.76
6. Step 6: Final answer
   x = 16,753.64