Finding the Fourth Proportional to 2,139.18, 3,208.29 and 579.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.18 : 3,208.29 = 579.32 : x
2. Step 2: Convert to fraction form
   2,139.18/3,208.29 = 579.32/x
3. Step 3: Cross multiply
   2,139.18x = 3,208.29 × 579.32
4. Step 4: Simplify right side
   2,139.18x = 1,858,641.69
5. Step 5: Solve for x
   x = 1,858,641.69/2,139.18
6. Step 6: Final answer
   x = 868.86