Finding the Fourth Proportional to 31,078.72, 42,891.73 and 18,978.53

Step by Step Solution

1. Step 1: Write the proportion equation
   31,078.72 : 42,891.73 = 18,978.53 : x
2. Step 2: Convert to fraction form
   31,078.72/42,891.73 = 18,978.53/x
3. Step 3: Cross multiply
   31,078.72x = 42,891.73 × 18,978.53
4. Step 4: Simplify right side
   31,078.72x = 814,022,044.34
5. Step 5: Solve for x
   x = 814,022,044.34/31,078.72
6. Step 6: Final answer
   x = 26,192.27