Finding the Fourth Proportional to 3,855.12, 5,320.06 and 2,086.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,855.12 : 5,320.06 = 2,086.72 : x
2. Step 2: Convert to fraction form
   3,855.12/5,320.06 = 2,086.72/x
3. Step 3: Cross multiply
   3,855.12x = 5,320.06 × 2,086.72
4. Step 4: Simplify right side
   3,855.12x = 11,101,498.75
5. Step 5: Solve for x
   x = 11,101,498.75/3,855.12
6. Step 6: Final answer
   x = 2,879.68