Finding the Fourth Proportional to 2,082.78, 2,874.20 and 1,138.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,082.78 : 2,874.20 = 1,138.56 : x
2. Step 2: Convert to fraction form
   2,082.78/2,874.20 = 1,138.56/x
3. Step 3: Cross multiply
   2,082.78x = 2,874.20 × 1,138.56
4. Step 4: Simplify right side
   2,082.78x = 3,272,449.15
5. Step 5: Solve for x
   x = 3,272,449.15/2,082.78
6. Step 6: Final answer
   x = 1,571.19