Finding the Fourth Proportional to 2,119.21, 3,179.83 and 820.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,119.21 : 3,179.83 = 820.38 : x
2. Step 2: Convert to fraction form
   2,119.21/3,179.83 = 820.38/x
3. Step 3: Cross multiply
   2,119.21x = 3,179.83 × 820.38
4. Step 4: Simplify right side
   2,119.21x = 2,608,653.04
5. Step 5: Solve for x
   x = 2,608,653.04/2,119.21
6. Step 6: Final answer
   x = 1,230.96