Finding the Fourth Proportional to 8,662.80, 12,969.90 and 8,662.80

Step by Step Solution

1. Step 1: Write the proportion equation
   8,662.80 : 12,969.90 = 8,662.80 : x
2. Step 2: Convert to fraction form
   8,662.80/12,969.90 = 8,662.80/x
3. Step 3: Cross multiply
   8,662.80x = 12,969.90 × 8,662.80
4. Step 4: Simplify right side
   8,662.80x = 112,355,649.72
5. Step 5: Solve for x
   x = 112,355,649.72/8,662.80
6. Step 6: Final answer
   x = 12,969.90