Finding the Fourth Proportional to 8,678.69, 13,015.35 and 3,131.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,678.69 : 13,015.35 = 3,131.31 : x
2. Step 2: Convert to fraction form
   8,678.69/13,015.35 = 3,131.31/x
3. Step 3: Cross multiply
   8,678.69x = 13,015.35 × 3,131.31
4. Step 4: Simplify right side
   8,678.69x = 40,755,095.61
5. Step 5: Solve for x
   x = 40,755,095.61/8,678.69
6. Step 6: Final answer
   x = 4,696.00