Finding the Third Proportional to 410,140 and 642,090

Step by Step Solution

1. Step 1: Write the proportion equation
   410,140 : 642,090 = 642,090 : x
2. Step 2: Convert to fraction form
   410,140/642,090 = 642,090/x
3. Step 3: Cross multiply
   410,140x = 642,090 × 642,090
4. Step 4: Simplify right side
   410,140x = 412,279,568,100
5. Step 5: Solve for x
   x = 412,279,568,100/410,140
6. Step 6: Final answer
   x = 1,005,216.68