Finding the Third Proportional to 139,878 and 209,769

Step by Step Solution

1. Step 1: Write the proportion equation
   139,878 : 209,769 = 209,769 : x
2. Step 2: Convert to fraction form
   139,878/209,769 = 209,769/x
3. Step 3: Cross multiply
   139,878x = 209,769 × 209,769
4. Step 4: Simplify right side
   139,878x = 44,003,033,361
5. Step 5: Solve for x
   x = 44,003,033,361/139,878
6. Step 6: Final answer
   x = 314,581.52