Finding the Fourth Proportional to 21,142.23, 31,714.82 and 8,491.98

Step by Step Solution

1. Step 1: Write the proportion equation
   21,142.23 : 31,714.82 = 8,491.98 : x
2. Step 2: Convert to fraction form
   21,142.23/31,714.82 = 8,491.98/x
3. Step 3: Cross multiply
   21,142.23x = 31,714.82 × 8,491.98
4. Step 4: Simplify right side
   21,142.23x = 269,321,574.68
5. Step 5: Solve for x
   x = 269,321,574.68/21,142.23
6. Step 6: Final answer
   x = 12,738.56