Finding the Fourth Proportional to 31,080.63, 42,878.43 and 21,654.66

Step by Step Solution

1. Step 1: Write the proportion equation
   31,080.63 : 42,878.43 = 21,654.66 : x
2. Step 2: Convert to fraction form
   31,080.63/42,878.43 = 21,654.66/x
3. Step 3: Cross multiply
   31,080.63x = 42,878.43 × 21,654.66
4. Step 4: Simplify right side
   31,080.63x = 928,517,822.98
5. Step 5: Solve for x
   x = 928,517,822.98/31,080.63
6. Step 6: Final answer
   x = 29,874.49