Finding the Fourth Proportional to 3,865.86, 5,339.89 and 2,859.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,865.86 : 5,339.89 = 2,859.61 : x
2. Step 2: Convert to fraction form
   3,865.86/5,339.89 = 2,859.61/x
3. Step 3: Cross multiply
   3,865.86x = 5,339.89 × 2,859.61
4. Step 4: Simplify right side
   3,865.86x = 15,270,026.50
5. Step 5: Solve for x
   x = 15,270,026.50/3,865.86
6. Step 6: Final answer
   x = 3,949.97