Finding the Fourth Proportional to 1,022.95, 1,411.67 and 557.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,022.95 : 1,411.67 = 557.20 : x
2. Step 2: Convert to fraction form
   1,022.95/1,411.67 = 557.20/x
3. Step 3: Cross multiply
   1,022.95x = 1,411.67 × 557.20
4. Step 4: Simplify right side
   1,022.95x = 786,582.52
5. Step 5: Solve for x
   x = 786,582.52/1,022.95
6. Step 6: Final answer
   x = 768.94