Finding the Third Proportional to 386,978 and 586,308

Step by Step Solution

1. Step 1: Write the proportion equation
   386,978 : 586,308 = 586,308 : x
2. Step 2: Convert to fraction form
   386,978/586,308 = 586,308/x
3. Step 3: Cross multiply
   386,978x = 586,308 × 586,308
4. Step 4: Simplify right side
   386,978x = 343,757,070,864
5. Step 5: Solve for x
   x = 343,757,070,864/386,978
6. Step 6: Final answer
   x = 888,311.66