Finding the Third Proportional to 309,142.50 and 671,159.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,142.50 : 671,159.50 = 671,159.50 : x
2. Step 2: Convert to fraction form
   309,142.50/671,159.50 = 671,159.50/x
3. Step 3: Cross multiply
   309,142.50x = 671,159.50 × 671,159.50
4. Step 4: Simplify right side
   309,142.50x = 450,455,074,440.25
5. Step 5: Solve for x
   x = 450,455,074,440.25/309,142.50
6. Step 6: Final answer
   x = 1,457,111.44