Finding the Fourth Proportional to 81,768.10, 122,656.20 and 42,402.10

Step by Step Solution

1. Step 1: Write the proportion equation
   81,768.10 : 122,656.20 = 42,402.10 : x
2. Step 2: Convert to fraction form
   81,768.10/122,656.20 = 42,402.10/x
3. Step 3: Cross multiply
   81,768.10x = 122,656.20 × 42,402.10
4. Step 4: Simplify right side
   81,768.10x = 5,200,880,458.02
5. Step 5: Solve for x
   x = 5,200,880,458.02/81,768.10
6. Step 6: Final answer
   x = 63,605.25