Finding the Fourth Proportional to 2,772.78, 4,158.02 and 1,128.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,772.78 : 4,158.02 = 1,128.21 : x
2. Step 2: Convert to fraction form
   2,772.78/4,158.02 = 1,128.21/x
3. Step 3: Cross multiply
   2,772.78x = 4,158.02 × 1,128.21
4. Step 4: Simplify right side
   2,772.78x = 4,691,122.56
5. Step 5: Solve for x
   x = 4,691,122.56/2,772.78
6. Step 6: Final answer
   x = 1,691.85