Finding the Fourth Proportional to 3,605.72, 5,405.60 and 1,139

Step by Step Solution

1. Step 1: Write the proportion equation
   3,605.72 : 5,405.60 = 1,139 : x
2. Step 2: Convert to fraction form
   3,605.72/5,405.60 = 1,139/x
3. Step 3: Cross multiply
   3,605.72x = 5,405.60 × 1,139
4. Step 4: Simplify right side
   3,605.72x = 6,156,978.40
5. Step 5: Solve for x
   x = 6,156,978.40/3,605.72
6. Step 6: Final answer
   x = 1,707.56