Finding the Third Proportional to 405,643.50 and 865,579.50

Step by Step Solution

1. Step 1: Write the proportion equation
   405,643.50 : 865,579.50 = 865,579.50 : x
2. Step 2: Convert to fraction form
   405,643.50/865,579.50 = 865,579.50/x
3. Step 3: Cross multiply
   405,643.50x = 865,579.50 × 865,579.50
4. Step 4: Simplify right side
   405,643.50x = 749,227,870,820.25
5. Step 5: Solve for x
   x = 749,227,870,820.25/405,643.50
6. Step 6: Final answer
   x = 1,847,010.67