Finding the Fourth Proportional to 8,664.89, 12,986.54 and 3,979.92

Step by Step Solution

1. Step 1: Write the proportion equation
   8,664.89 : 12,986.54 = 3,979.92 : x
2. Step 2: Convert to fraction form
   8,664.89/12,986.54 = 3,979.92/x
3. Step 3: Cross multiply
   8,664.89x = 12,986.54 × 3,979.92
4. Step 4: Simplify right side
   8,664.89x = 51,685,370.38
5. Step 5: Solve for x
   x = 51,685,370.38/8,664.89
6. Step 6: Final answer
   x = 5,964.92