Finding the Third Proportional to 138,690 and 209,016

Step by Step Solution

1. Step 1: Write the proportion equation
   138,690 : 209,016 = 209,016 : x
2. Step 2: Convert to fraction form
   138,690/209,016 = 209,016/x
3. Step 3: Cross multiply
   138,690x = 209,016 × 209,016
4. Step 4: Simplify right side
   138,690x = 43,687,688,256
5. Step 5: Solve for x
   x = 43,687,688,256/138,690
6. Step 6: Final answer
   x = 315,002.44