Finding the Third Proportional to 391,978 and 552,008

Step by Step Solution

1. Step 1: Write the proportion equation
   391,978 : 552,008 = 552,008 : x
2. Step 2: Convert to fraction form
   391,978/552,008 = 552,008/x
3. Step 3: Cross multiply
   391,978x = 552,008 × 552,008
4. Step 4: Simplify right side
   391,978x = 304,712,832,064
5. Step 5: Solve for x
   x = 304,712,832,064/391,978
6. Step 6: Final answer
   x = 777,372.28