Finding the Fourth Proportional to 1,288.49, 1,782.81 and 1,123.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.49 : 1,782.81 = 1,123.05 : x
2. Step 2: Convert to fraction form
   1,288.49/1,782.81 = 1,123.05/x
3. Step 3: Cross multiply
   1,288.49x = 1,782.81 × 1,123.05
4. Step 4: Simplify right side
   1,288.49x = 2,002,179.16
5. Step 5: Solve for x
   x = 2,002,179.16/1,288.49
6. Step 6: Final answer
   x = 1,553.90