Finding the Third Proportional to 638,842 and 1,407,308

Step by Step Solution

1. Step 1: Write the proportion equation
   638,842 : 1,407,308 = 1,407,308 : x
2. Step 2: Convert to fraction form
   638,842/1,407,308 = 1,407,308/x
3. Step 3: Cross multiply
   638,842x = 1,407,308 × 1,407,308
4. Step 4: Simplify right side
   638,842x = 1,980,515,806,864
5. Step 5: Solve for x
   x = 1,980,515,806,864/638,842
6. Step 6: Final answer
   x = 3,100,165.31