Finding the Third Proportional to 309,998 and 438,767.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,998 : 438,767.50 = 438,767.50 : x
2. Step 2: Convert to fraction form
   309,998/438,767.50 = 438,767.50/x
3. Step 3: Cross multiply
   309,998x = 438,767.50 × 438,767.50
4. Step 4: Simplify right side
   309,998x = 192,516,919,056.25
5. Step 5: Solve for x
   x = 192,516,919,056.25/309,998
6. Step 6: Final answer
   x = 621,026.33