Finding the Third Proportional to 9,660 and 12,890

Step by Step Solution

1. Step 1: Write the proportion equation
   9,660 : 12,890 = 12,890 : x
2. Step 2: Convert to fraction form
   9,660/12,890 = 12,890/x
3. Step 3: Cross multiply
   9,660x = 12,890 × 12,890
4. Step 4: Simplify right side
   9,660x = 166,152,100
5. Step 5: Solve for x
   x = 166,152,100/9,660
6. Step 6: Final answer
   x = 17,200.01