Finding the Third Proportional to 642,978 and 1,400,274

Step by Step Solution

1. Step 1: Write the proportion equation
   642,978 : 1,400,274 = 1,400,274 : x
2. Step 2: Convert to fraction form
   642,978/1,400,274 = 1,400,274/x
3. Step 3: Cross multiply
   642,978x = 1,400,274 × 1,400,274
4. Step 4: Simplify right side
   642,978x = 1,960,767,275,076
5. Step 5: Solve for x
   x = 1,960,767,275,076/642,978
6. Step 6: Final answer
   x = 3,049,509.12