Finding the Fourth Proportional to 81,396.72, 122,282.21 and 57,436.16

Step by Step Solution

1. Step 1: Write the proportion equation
   81,396.72 : 122,282.21 = 57,436.16 : x
2. Step 2: Convert to fraction form
   81,396.72/122,282.21 = 57,436.16/x
3. Step 3: Cross multiply
   81,396.72x = 122,282.21 × 57,436.16
4. Step 4: Simplify right side
   81,396.72x = 7,023,420,110.89
5. Step 5: Solve for x
   x = 7,023,420,110.89/81,396.72
6. Step 6: Final answer
   x = 86,286.28