Finding the Fourth Proportional to 2,083.90, 2,875.78 and 1,139.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,083.90 : 2,875.78 = 1,139.78 : x
2. Step 2: Convert to fraction form
   2,083.90/2,875.78 = 1,139.78/x
3. Step 3: Cross multiply
   2,083.90x = 2,875.78 × 1,139.78
4. Step 4: Simplify right side
   2,083.90x = 3,277,754.36
5. Step 5: Solve for x
   x = 3,277,754.36/2,083.90
6. Step 6: Final answer
   x = 1,572.89