Finding the Fourth Proportional to 31,665.58, 43,691.30 and 18,916.74

Step by Step Solution

1. Step 1: Write the proportion equation
   31,665.58 : 43,691.30 = 18,916.74 : x
2. Step 2: Convert to fraction form
   31,665.58/43,691.30 = 18,916.74/x
3. Step 3: Cross multiply
   31,665.58x = 43,691.30 × 18,916.74
4. Step 4: Simplify right side
   31,665.58x = 826,496,938.72
5. Step 5: Solve for x
   x = 826,496,938.72/31,665.58
6. Step 6: Final answer
   x = 26,100.80