Finding the Fourth Proportional to 2,209.55, 3,311.87 and 909.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,209.55 : 3,311.87 = 909.89 : x
2. Step 2: Convert to fraction form
   2,209.55/3,311.87 = 909.89/x
3. Step 3: Cross multiply
   2,209.55x = 3,311.87 × 909.89
4. Step 4: Simplify right side
   2,209.55x = 3,013,432.84
5. Step 5: Solve for x
   x = 3,013,432.84/2,209.55
6. Step 6: Final answer
   x = 1,363.82