Finding the Fourth Proportional to 2,120.52, 3,179.55 and 820.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,120.52 : 3,179.55 = 820.47 : x
2. Step 2: Convert to fraction form
   2,120.52/3,179.55 = 820.47/x
3. Step 3: Cross multiply
   2,120.52x = 3,179.55 × 820.47
4. Step 4: Simplify right side
   2,120.52x = 2,608,725.39
5. Step 5: Solve for x
   x = 2,608,725.39/2,120.52
6. Step 6: Final answer
   x = 1,230.23