Finding the Fourth Proportional to 1,123.50, 1,545.20 and 902.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.50 : 1,545.20 = 902.10 : x
2. Step 2: Convert to fraction form
   1,123.50/1,545.20 = 902.10/x
3. Step 3: Cross multiply
   1,123.50x = 1,545.20 × 902.10
4. Step 4: Simplify right side
   1,123.50x = 1,393,924.92
5. Step 5: Solve for x
   x = 1,393,924.92/1,123.50
6. Step 6: Final answer
   x = 1,240.70