Finding the Third Proportional to 305,220 and 638,320.50

Step by Step Solution

1. Step 1: Write the proportion equation
   305,220 : 638,320.50 = 638,320.50 : x
2. Step 2: Convert to fraction form
   305,220/638,320.50 = 638,320.50/x
3. Step 3: Cross multiply
   305,220x = 638,320.50 × 638,320.50
4. Step 4: Simplify right side
   305,220x = 407,453,060,720.25
5. Step 5: Solve for x
   x = 407,453,060,720.25/305,220
6. Step 6: Final answer
   x = 1,334,948.76