Finding the Third Proportional to 8,560 and 13,139

Step by Step Solution

1. Step 1: Write the proportion equation
   8,560 : 13,139 = 13,139 : x
2. Step 2: Convert to fraction form
   8,560/13,139 = 13,139/x
3. Step 3: Cross multiply
   8,560x = 13,139 × 13,139
4. Step 4: Simplify right side
   8,560x = 172,633,321
5. Step 5: Solve for x
   x = 172,633,321/8,560
6. Step 6: Final answer
   x = 20,167.44