Finding the Fourth Proportional to 8,643.90, 12,878.82 and 8,078.10

Step by Step Solution

1. Step 1: Write the proportion equation
   8,643.90 : 12,878.82 = 8,078.10 : x
2. Step 2: Convert to fraction form
   8,643.90/12,878.82 = 8,078.10/x
3. Step 3: Cross multiply
   8,643.90x = 12,878.82 × 8,078.10
4. Step 4: Simplify right side
   8,643.90x = 104,036,395.84
5. Step 5: Solve for x
   x = 104,036,395.84/8,643.90
6. Step 6: Final answer
   x = 12,035.82