Finding the Fourth Proportional to 2,139.27, 3,205.25 and 1,728.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.27 : 3,205.25 = 1,728.60 : x
2. Step 2: Convert to fraction form
   2,139.27/3,205.25 = 1,728.60/x
3. Step 3: Cross multiply
   2,139.27x = 3,205.25 × 1,728.60
4. Step 4: Simplify right side
   2,139.27x = 5,540,583.45
5. Step 5: Solve for x
   x = 5,540,583.45/2,139.27
6. Step 6: Final answer
   x = 2,589.95