Finding the Fourth Proportional to 2,139.32, 3,209.18 and 579.34

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.32 : 3,209.18 = 579.34 : x
2. Step 2: Convert to fraction form
   2,139.32/3,209.18 = 579.34/x
3. Step 3: Cross multiply
   2,139.32x = 3,209.18 × 579.34
4. Step 4: Simplify right side
   2,139.32x = 1,859,191.03
5. Step 5: Solve for x
   x = 1,859,191.03/2,139.32
6. Step 6: Final answer
   x = 869.06