Finding the Third Proportional to 309,217.50 and 671,310

Step by Step Solution

1. Step 1: Write the proportion equation
   309,217.50 : 671,310 = 671,310 : x
2. Step 2: Convert to fraction form
   309,217.50/671,310 = 671,310/x
3. Step 3: Cross multiply
   309,217.50x = 671,310 × 671,310
4. Step 4: Simplify right side
   309,217.50x = 450,657,116,100
5. Step 5: Solve for x
   x = 450,657,116,100/309,217.50
6. Step 6: Final answer
   x = 1,457,411.42