Finding the Fourth Proportional to 1,123.87, 1,685.31 and 603.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.87 : 1,685.31 = 603.78 : x
2. Step 2: Convert to fraction form
   1,123.87/1,685.31 = 603.78/x
3. Step 3: Cross multiply
   1,123.87x = 1,685.31 × 603.78
4. Step 4: Simplify right side
   1,123.87x = 1,017,556.47
5. Step 5: Solve for x
   x = 1,017,556.47/1,123.87
6. Step 6: Final answer
   x = 905.40