Finding the Third Proportional to 390,064,900 and 812,414,456

Step by Step Solution

1. Step 1: Write the proportion equation
   390,064,900 : 812,414,456 = 812,414,456 : x
2. Step 2: Convert to fraction form
   390,064,900/812,414,456 = 812,414,456/x
3. Step 3: Cross multiply
   390,064,900x = 812,414,456 × 812,414,456
4. Step 4: Simplify right side
   390,064,900x = 660,017,248,317,775,872
5. Step 5: Solve for x
   x = 660,017,248,317,775,872/390,064,900
6. Step 6: Final answer
   x = 1,692,070,340.90