Finding the Fourth Proportional to 81,772.10, 122,662.20 and 42,406.10

Step by Step Solution

1. Step 1: Write the proportion equation
   81,772.10 : 122,662.20 = 42,406.10 : x
2. Step 2: Convert to fraction form
   81,772.10/122,662.20 = 42,406.10/x
3. Step 3: Cross multiply
   81,772.10x = 122,662.20 × 42,406.10
4. Step 4: Simplify right side
   81,772.10x = 5,201,625,519.42
5. Step 5: Solve for x
   x = 5,201,625,519.42/81,772.10
6. Step 6: Final answer
   x = 63,611.25