Finding the Fourth Proportional to 2,900.31, 4,350.72 and 820.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,900.31 : 4,350.72 = 820.35 : x
2. Step 2: Convert to fraction form
   2,900.31/4,350.72 = 820.35/x
3. Step 3: Cross multiply
   2,900.31x = 4,350.72 × 820.35
4. Step 4: Simplify right side
   2,900.31x = 3,569,113.15
5. Step 5: Solve for x
   x = 3,569,113.15/2,900.31
6. Step 6: Final answer
   x = 1,230.60