Finding the Fourth Proportional to 1,288.54, 1,932.12 and 557.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.54 : 1,932.12 = 557.78 : x
2. Step 2: Convert to fraction form
   1,288.54/1,932.12 = 557.78/x
3. Step 3: Cross multiply
   1,288.54x = 1,932.12 × 557.78
4. Step 4: Simplify right side
   1,288.54x = 1,077,697.89
5. Step 5: Solve for x
   x = 1,077,697.89/1,288.54
6. Step 6: Final answer
   x = 836.37