Finding the Third Proportional to 646,978 and 1,407,320

Step by Step Solution

1. Step 1: Write the proportion equation
   646,978 : 1,407,320 = 1,407,320 : x
2. Step 2: Convert to fraction form
   646,978/1,407,320 = 1,407,320/x
3. Step 3: Cross multiply
   646,978x = 1,407,320 × 1,407,320
4. Step 4: Simplify right side
   646,978x = 1,980,549,582,400
5. Step 5: Solve for x
   x = 1,980,549,582,400/646,978
6. Step 6: Final answer
   x = 3,061,231.73