Finding the Third Proportional to 309,078 and 478,318.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,078 : 478,318.50 = 478,318.50 : x
2. Step 2: Convert to fraction form
   309,078/478,318.50 = 478,318.50/x
3. Step 3: Cross multiply
   309,078x = 478,318.50 × 478,318.50
4. Step 4: Simplify right side
   309,078x = 228,788,587,442.25
5. Step 5: Solve for x
   x = 228,788,587,442.25/309,078
6. Step 6: Final answer
   x = 740,229.29