Finding the Fourth Proportional to 21,031.72, 29,020.48 and 12,077.98

Step by Step Solution

1. Step 1: Write the proportion equation
   21,031.72 : 29,020.48 = 12,077.98 : x
2. Step 2: Convert to fraction form
   21,031.72/29,020.48 = 12,077.98/x
3. Step 3: Cross multiply
   21,031.72x = 29,020.48 × 12,077.98
4. Step 4: Simplify right side
   21,031.72x = 350,508,777.03
5. Step 5: Solve for x
   x = 350,508,777.03/21,031.72
6. Step 6: Final answer
   x = 16,665.72