Finding the Third Proportional to 320,609 and 500,320.50

Step by Step Solution

1. Step 1: Write the proportion equation
   320,609 : 500,320.50 = 500,320.50 : x
2. Step 2: Convert to fraction form
   320,609/500,320.50 = 500,320.50/x
3. Step 3: Cross multiply
   320,609x = 500,320.50 × 500,320.50
4. Step 4: Simplify right side
   320,609x = 250,320,602,720.25
5. Step 5: Solve for x
   x = 250,320,602,720.25/320,609
6. Step 6: Final answer
   x = 780,765.99