Finding the Third Proportional to 338,021.50 and 685,377

Step by Step Solution

1. Step 1: Write the proportion equation
   338,021.50 : 685,377 = 685,377 : x
2. Step 2: Convert to fraction form
   338,021.50/685,377 = 685,377/x
3. Step 3: Cross multiply
   338,021.50x = 685,377 × 685,377
4. Step 4: Simplify right side
   338,021.50x = 469,741,632,129
5. Step 5: Solve for x
   x = 469,741,632,129/338,021.50
6. Step 6: Final answer
   x = 1,389,679.75