Finding the Third Proportional to 309,699 and 478,630.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,699 : 478,630.50 = 478,630.50 : x
2. Step 2: Convert to fraction form
   309,699/478,630.50 = 478,630.50/x
3. Step 3: Cross multiply
   309,699x = 478,630.50 × 478,630.50
4. Step 4: Simplify right side
   309,699x = 229,087,155,530.25
5. Step 5: Solve for x
   x = 229,087,155,530.25/309,699
6. Step 6: Final answer
   x = 739,709.06