Finding the Third Proportional to 258,684 and 377,978

Step by Step Solution

1. Step 1: Write the proportion equation
   258,684 : 377,978 = 377,978 : x
2. Step 2: Convert to fraction form
   258,684/377,978 = 377,978/x
3. Step 3: Cross multiply
   258,684x = 377,978 × 377,978
4. Step 4: Simplify right side
   258,684x = 142,867,368,484
5. Step 5: Solve for x
   x = 142,867,368,484/258,684
6. Step 6: Final answer
   x = 552,285.29