Finding the Fourth Proportional to 1,222.55, 1,684.31 and 903.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.55 : 1,684.31 = 903.61 : x
2. Step 2: Convert to fraction form
   1,222.55/1,684.31 = 903.61/x
3. Step 3: Cross multiply
   1,222.55x = 1,684.31 × 903.61
4. Step 4: Simplify right side
   1,222.55x = 1,521,946.42
5. Step 5: Solve for x
   x = 1,521,946.42/1,222.55
6. Step 6: Final answer
   x = 1,244.90