Finding the Fourth Proportional to 81,912.16, 112,978.32 and 56,426.72

Step by Step Solution

1. Step 1: Write the proportion equation
   81,912.16 : 112,978.32 = 56,426.72 : x
2. Step 2: Convert to fraction form
   81,912.16/112,978.32 = 56,426.72/x
3. Step 3: Cross multiply
   81,912.16x = 112,978.32 × 56,426.72
4. Step 4: Simplify right side
   81,912.16x = 6,374,996,028.71
5. Step 5: Solve for x
   x = 6,374,996,028.71/81,912.16
6. Step 6: Final answer
   x = 77,827.22