Finding the Third Proportional to 9,640 and 12,866

Step by Step Solution

1. Step 1: Write the proportion equation
   9,640 : 12,866 = 12,866 : x
2. Step 2: Convert to fraction form
   9,640/12,866 = 12,866/x
3. Step 3: Cross multiply
   9,640x = 12,866 × 12,866
4. Step 4: Simplify right side
   9,640x = 165,533,956
5. Step 5: Solve for x
   x = 165,533,956/9,640
6. Step 6: Final answer
   x = 17,171.57