Finding the Fourth Proportional to 8,665.27, 12,990.08 and 3,117.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,665.27 : 12,990.08 = 3,117.31 : x
2. Step 2: Convert to fraction form
   8,665.27/12,990.08 = 3,117.31/x
3. Step 3: Cross multiply
   8,665.27x = 12,990.08 × 3,117.31
4. Step 4: Simplify right side
   8,665.27x = 40,494,081.60
5. Step 5: Solve for x
   x = 40,494,081.60/8,665.27
6. Step 6: Final answer
   x = 4,673.15