Finding the Third Proportional to 398,026 and 840,978

Step by Step Solution

1. Step 1: Write the proportion equation
   398,026 : 840,978 = 840,978 : x
2. Step 2: Convert to fraction form
   398,026/840,978 = 840,978/x
3. Step 3: Cross multiply
   398,026x = 840,978 × 840,978
4. Step 4: Simplify right side
   398,026x = 707,243,996,484
5. Step 5: Solve for x
   x = 707,243,996,484/398,026
6. Step 6: Final answer
   x = 1,776,878.89