Finding the Fourth Proportional to 3,856.86, 5,780.16 and 2,101.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.86 : 5,780.16 = 2,101.86 : x
2. Step 2: Convert to fraction form
   3,856.86/5,780.16 = 2,101.86/x
3. Step 3: Cross multiply
   3,856.86x = 5,780.16 × 2,101.86
4. Step 4: Simplify right side
   3,856.86x = 12,149,087.10
5. Step 5: Solve for x
   x = 12,149,087.10/3,856.86
6. Step 6: Final answer
   x = 3,149.99