Finding the Fourth Proportional to 3,879.88, 5,354.25 and 2,111.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,879.88 : 5,354.25 = 2,111.50 : x
2. Step 2: Convert to fraction form
   3,879.88/5,354.25 = 2,111.50/x
3. Step 3: Cross multiply
   3,879.88x = 5,354.25 × 2,111.50
4. Step 4: Simplify right side
   3,879.88x = 11,305,472.10
5. Step 5: Solve for x
   x = 11,305,472.10/3,879.88
6. Step 6: Final answer
   x = 2,913.88