Finding the Third Proportional to 259,686 and 388,494

Step by Step Solution

1. Step 1: Write the proportion equation
   259,686 : 388,494 = 388,494 : x
2. Step 2: Convert to fraction form
   259,686/388,494 = 388,494/x
3. Step 3: Cross multiply
   259,686x = 388,494 × 388,494
4. Step 4: Simplify right side
   259,686x = 150,927,588,036
5. Step 5: Solve for x
   x = 150,927,588,036/259,686
6. Step 6: Final answer
   x = 581,192.63