Finding the Fourth Proportional to 85,820.05, 128,562.49 and 40,777.31

Step by Step Solution

1. Step 1: Write the proportion equation
   85,820.05 : 128,562.49 = 40,777.31 : x
2. Step 2: Convert to fraction form
   85,820.05/128,562.49 = 40,777.31/x
3. Step 3: Cross multiply
   85,820.05x = 128,562.49 × 40,777.31
4. Step 4: Simplify right side
   85,820.05x = 5,242,432,509.10
5. Step 5: Solve for x
   x = 5,242,432,509.10/85,820.05
6. Step 6: Final answer
   x = 61,086.34