Finding the Fourth Proportional to 2,139.50, 3,209.15 and 823.01

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.50 : 3,209.15 = 823.01 : x
2. Step 2: Convert to fraction form
   2,139.50/3,209.15 = 823.01/x
3. Step 3: Cross multiply
   2,139.50x = 3,209.15 × 823.01
4. Step 4: Simplify right side
   2,139.50x = 2,641,142.38
5. Step 5: Solve for x
   x = 2,641,142.38/2,139.50
6. Step 6: Final answer
   x = 1,234.47