Finding the Fourth Proportional to 1,139.89, 1,710.05 and 409.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.89 : 1,710.05 = 409.43 : x
2. Step 2: Convert to fraction form
   1,139.89/1,710.05 = 409.43/x
3. Step 3: Cross multiply
   1,139.89x = 1,710.05 × 409.43
4. Step 4: Simplify right side
   1,139.89x = 700,145.77
5. Step 5: Solve for x
   x = 700,145.77/1,139.89
6. Step 6: Final answer
   x = 614.22