Finding the Fourth Proportional to 81,908.10, 122,866.20 and 42,542.10

Step by Step Solution

1. Step 1: Write the proportion equation
   81,908.10 : 122,866.20 = 42,542.10 : x
2. Step 2: Convert to fraction form
   81,908.10/122,866.20 = 42,542.10/x
3. Step 3: Cross multiply
   81,908.10x = 122,866.20 × 42,542.10
4. Step 4: Simplify right side
   81,908.10x = 5,226,986,167.02
5. Step 5: Solve for x
   x = 5,226,986,167.02/81,908.10
6. Step 6: Final answer
   x = 63,815.25