Finding the Fourth Proportional to 2,078.40, 3,111.06 and 1,139.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.40 : 3,111.06 = 1,139.96 : x
2. Step 2: Convert to fraction form
   2,078.40/3,111.06 = 1,139.96/x
3. Step 3: Cross multiply
   2,078.40x = 3,111.06 × 1,139.96
4. Step 4: Simplify right side
   2,078.40x = 3,546,483.96
5. Step 5: Solve for x
   x = 3,546,483.96/2,078.40
6. Step 6: Final answer
   x = 1,706.35