Finding the Fourth Proportional to 85,820.31, 128,562.86 and 40,777.56

Step by Step Solution

1. Step 1: Write the proportion equation
   85,820.31 : 128,562.86 = 40,777.56 : x
2. Step 2: Convert to fraction form
   85,820.31/128,562.86 = 40,777.56/x
3. Step 3: Cross multiply
   85,820.31x = 128,562.86 × 40,777.56
4. Step 4: Simplify right side
   85,820.31x = 5,242,479,737.42
5. Step 5: Solve for x
   x = 5,242,479,737.42/85,820.31
6. Step 6: Final answer
   x = 61,086.70