Finding the Third Proportional to 420,404 and 634,978

Step by Step Solution

1. Step 1: Write the proportion equation
   420,404 : 634,978 = 634,978 : x
2. Step 2: Convert to fraction form
   420,404/634,978 = 634,978/x
3. Step 3: Cross multiply
   420,404x = 634,978 × 634,978
4. Step 4: Simplify right side
   420,404x = 403,197,060,484
5. Step 5: Solve for x
   x = 403,197,060,484/420,404
6. Step 6: Final answer
   x = 959,070.47