Finding the Fourth Proportional to 3,530.55, 5,285.30 and 2,139.69

Step by Step Solution

1. Step 1: Write the proportion equation
   3,530.55 : 5,285.30 = 2,139.69 : x
2. Step 2: Convert to fraction form
   3,530.55/5,285.30 = 2,139.69/x
3. Step 3: Cross multiply
   3,530.55x = 5,285.30 × 2,139.69
4. Step 4: Simplify right side
   3,530.55x = 11,308,892.86
5. Step 5: Solve for x
   x = 11,308,892.86/3,530.55
6. Step 6: Final answer
   x = 3,203.15