Finding the Fourth Proportional to 3,105.55, 4,285.73 and 1,689.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,105.55 : 4,285.73 = 1,689.31 : x
2. Step 2: Convert to fraction form
   3,105.55/4,285.73 = 1,689.31/x
3. Step 3: Cross multiply
   3,105.55x = 4,285.73 × 1,689.31
4. Step 4: Simplify right side
   3,105.55x = 7,239,926.55
5. Step 5: Solve for x
   x = 7,239,926.55/3,105.55
6. Step 6: Final answer
   x = 2,331.29