Finding the Third Proportional to 309,219 and 671,313.75

Step by Step Solution

1. Step 1: Write the proportion equation
   309,219 : 671,313.75 = 671,313.75 : x
2. Step 2: Convert to fraction form
   309,219/671,313.75 = 671,313.75/x
3. Step 3: Cross multiply
   309,219x = 671,313.75 × 671,313.75
4. Step 4: Simplify right side
   309,219x = 450,662,150,939.06
5. Step 5: Solve for x
   x = 450,662,150,939.06/309,219
6. Step 6: Final answer
   x = 1,457,420.63