Finding the Third Proportional to 280,638 and 620,338.50

Step by Step Solution

1. Step 1: Write the proportion equation
   280,638 : 620,338.50 = 620,338.50 : x
2. Step 2: Convert to fraction form
   280,638/620,338.50 = 620,338.50/x
3. Step 3: Cross multiply
   280,638x = 620,338.50 × 620,338.50
4. Step 4: Simplify right side
   280,638x = 384,819,854,582.25
5. Step 5: Solve for x
   x = 384,819,854,582.25/280,638
6. Step 6: Final answer
   x = 1,371,232.17