Finding the Fourth Proportional to 1,643.10, 2,462.82 and 820.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,643.10 : 2,462.82 = 820.62 : x
2. Step 2: Convert to fraction form
   1,643.10/2,462.82 = 820.62/x
3. Step 3: Cross multiply
   1,643.10x = 2,462.82 × 820.62
4. Step 4: Simplify right side
   1,643.10x = 2,021,039.35
5. Step 5: Solve for x
   x = 2,021,039.35/1,643.10
6. Step 6: Final answer
   x = 1,230.02