Finding the Fourth Proportional to 2,154.91, 3,230.78 and 820.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,154.91 : 3,230.78 = 820.52 : x
2. Step 2: Convert to fraction form
   2,154.91/3,230.78 = 820.52/x
3. Step 3: Cross multiply
   2,154.91x = 3,230.78 × 820.52
4. Step 4: Simplify right side
   2,154.91x = 2,650,911.46
5. Step 5: Solve for x
   x = 2,650,911.46/2,154.91
6. Step 6: Final answer
   x = 1,230.17