Finding the Fourth Proportional to 8,426.28, 12,640.91 and 2,878.33

Step by Step Solution

1. Step 1: Write the proportion equation
   8,426.28 : 12,640.91 = 2,878.33 : x
2. Step 2: Convert to fraction form
   8,426.28/12,640.91 = 2,878.33/x
3. Step 3: Cross multiply
   8,426.28x = 12,640.91 × 2,878.33
4. Step 4: Simplify right side
   8,426.28x = 36,384,632.88
5. Step 5: Solve for x
   x = 36,384,632.88/8,426.28
6. Step 6: Final answer
   x = 4,317.99