Finding the Fourth Proportional to 2,209.78, 3,314.31 and 748.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,209.78 : 3,314.31 = 748.90 : x
2. Step 2: Convert to fraction form
   2,209.78/3,314.31 = 748.90/x
3. Step 3: Cross multiply
   2,209.78x = 3,314.31 × 748.90
4. Step 4: Simplify right side
   2,209.78x = 2,482,086.76
5. Step 5: Solve for x
   x = 2,482,086.76/2,209.78
6. Step 6: Final answer
   x = 1,123.23