Finding the Fourth Proportional to 2,083.78, 2,875.57 and 1,139.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,083.78 : 2,875.57 = 1,139.55 : x
2. Step 2: Convert to fraction form
   2,083.78/2,875.57 = 1,139.55/x
3. Step 3: Cross multiply
   2,083.78x = 2,875.57 × 1,139.55
4. Step 4: Simplify right side
   2,083.78x = 3,276,855.79
5. Step 5: Solve for x
   x = 3,276,855.79/2,083.78
6. Step 6: Final answer
   x = 1,572.55