Finding the Fourth Proportional to 1,123.40, 1,550.46 and 890.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.40 : 1,550.46 = 890.12 : x
2. Step 2: Convert to fraction form
   1,123.40/1,550.46 = 890.12/x
3. Step 3: Cross multiply
   1,123.40x = 1,550.46 × 890.12
4. Step 4: Simplify right side
   1,123.40x = 1,380,095.46
5. Step 5: Solve for x
   x = 1,380,095.46/1,123.40
6. Step 6: Final answer
   x = 1,228.50