Finding the Third Proportional to 9,309 and 12,643.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,309 : 12,643.50 = 12,643.50 : x
2. Step 2: Convert to fraction form
   9,309/12,643.50 = 12,643.50/x
3. Step 3: Cross multiply
   9,309x = 12,643.50 × 12,643.50
4. Step 4: Simplify right side
   9,309x = 159,858,092.25
5. Step 5: Solve for x
   x = 159,858,092.25/9,309
6. Step 6: Final answer
   x = 17,172.42