Finding the Third Proportional to 139,879.50 and 209,770.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,879.50 : 209,770.50 = 209,770.50 : x
2. Step 2: Convert to fraction form
   139,879.50/209,770.50 = 209,770.50/x
3. Step 3: Cross multiply
   139,879.50x = 209,770.50 × 209,770.50
4. Step 4: Simplify right side
   139,879.50x = 44,003,662,670.25
5. Step 5: Solve for x
   x = 44,003,662,670.25/139,879.50
6. Step 6: Final answer
   x = 314,582.64