Finding the Third Proportional to 156,921 and 322,109

Step by Step Solution

1. Step 1: Write the proportion equation
   156,921 : 322,109 = 322,109 : x
2. Step 2: Convert to fraction form
   156,921/322,109 = 322,109/x
3. Step 3: Cross multiply
   156,921x = 322,109 × 322,109
4. Step 4: Simplify right side
   156,921x = 103,754,207,881
5. Step 5: Solve for x
   x = 103,754,207,881/156,921
6. Step 6: Final answer
   x = 661,187.53