Finding the Fourth Proportional to 21,146.49, 31,719.96 and 8,663.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,146.49 : 31,719.96 = 8,663.31 : x
2. Step 2: Convert to fraction form
   21,146.49/31,719.96 = 8,663.31/x
3. Step 3: Cross multiply
   21,146.49x = 31,719.96 × 8,663.31
4. Step 4: Simplify right side
   21,146.49x = 274,799,846.67
5. Step 5: Solve for x
   x = 274,799,846.67/21,146.49
6. Step 6: Final answer
   x = 12,995.06