Finding the Fourth Proportional to 1,012.57, 1,397.46 and 570.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.57 : 1,397.46 = 570.55 : x
2. Step 2: Convert to fraction form
   1,012.57/1,397.46 = 570.55/x
3. Step 3: Cross multiply
   1,012.57x = 1,397.46 × 570.55
4. Step 4: Simplify right side
   1,012.57x = 797,320.80
5. Step 5: Solve for x
   x = 797,320.80/1,012.57
6. Step 6: Final answer
   x = 787.42