Finding the Fourth Proportional to 3,605.06, 5,405.72 and 1,139.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,605.06 : 5,405.72 = 1,139.42 : x
2. Step 2: Convert to fraction form
   3,605.06/5,405.72 = 1,139.42/x
3. Step 3: Cross multiply
   3,605.06x = 5,405.72 × 1,139.42
4. Step 4: Simplify right side
   3,605.06x = 6,159,385.48
5. Step 5: Solve for x
   x = 6,159,385.48/3,605.06
6. Step 6: Final answer
   x = 1,708.54