Finding the Third Proportional to 5,215,976 and 7,978,944

Step by Step Solution

1. Step 1: Write the proportion equation
   5,215,976 : 7,978,944 = 7,978,944 : x
2. Step 2: Convert to fraction form
   5,215,976/7,978,944 = 7,978,944/x
3. Step 3: Cross multiply
   5,215,976x = 7,978,944 × 7,978,944
4. Step 4: Simplify right side
   5,215,976x = 63,663,547,355,136
5. Step 5: Solve for x
   x = 63,663,547,355,136/5,215,976
6. Step 6: Final answer
   x = 12,205,490.85