Finding the Fourth Proportional to 8,111.25, 12,166.92 and 2,639.25

Step by Step Solution

1. Step 1: Write the proportion equation
   8,111.25 : 12,166.92 = 2,639.25 : x
2. Step 2: Convert to fraction form
   8,111.25/12,166.92 = 2,639.25/x
3. Step 3: Cross multiply
   8,111.25x = 12,166.92 × 2,639.25
4. Step 4: Simplify right side
   8,111.25x = 32,111,543.61
5. Step 5: Solve for x
   x = 32,111,543.61/8,111.25
6. Step 6: Final answer
   x = 3,958.89