Finding the Third Proportional to 320,648 and 500,380

Step by Step Solution

1. Step 1: Write the proportion equation
   320,648 : 500,380 = 500,380 : x
2. Step 2: Convert to fraction form
   320,648/500,380 = 500,380/x
3. Step 3: Cross multiply
   320,648x = 500,380 × 500,380
4. Step 4: Simplify right side
   320,648x = 250,380,144,400
5. Step 5: Solve for x
   x = 250,380,144,400/320,648
6. Step 6: Final answer
   x = 780,856.72