Finding the Fourth Proportional to 1,123.20, 1,549.88 and 625.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.20 : 1,549.88 = 625.78 : x
2. Step 2: Convert to fraction form
   1,123.20/1,549.88 = 625.78/x
3. Step 3: Cross multiply
   1,123.20x = 1,549.88 × 625.78
4. Step 4: Simplify right side
   1,123.20x = 969,883.91
5. Step 5: Solve for x
   x = 969,883.91/1,123.20
6. Step 6: Final answer
   x = 863.50