Finding the Fourth Proportional to 21,018.72, 29,010.78 and 12,070.92

Step by Step Solution

1. Step 1: Write the proportion equation
   21,018.72 : 29,010.78 = 12,070.92 : x
2. Step 2: Convert to fraction form
   21,018.72/29,010.78 = 12,070.92/x
3. Step 3: Cross multiply
   21,018.72x = 29,010.78 × 12,070.92
4. Step 4: Simplify right side
   21,018.72x = 350,186,804.52
5. Step 5: Solve for x
   x = 350,186,804.52/21,018.72
6. Step 6: Final answer
   x = 16,660.71