Finding the Fourth Proportional to 2,620.01, 3,929.82 and 1,139.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.01 : 3,929.82 = 1,139.20 : x
2. Step 2: Convert to fraction form
   2,620.01/3,929.82 = 1,139.20/x
3. Step 3: Cross multiply
   2,620.01x = 3,929.82 × 1,139.20
4. Step 4: Simplify right side
   2,620.01x = 4,476,836.85
5. Step 5: Solve for x
   x = 4,476,836.85/2,620.01
6. Step 6: Final answer
   x = 1,708.71