Finding the Third Proportional to 259,686 and 388,488

Step by Step Solution

1. Step 1: Write the proportion equation
   259,686 : 388,488 = 388,488 : x
2. Step 2: Convert to fraction form
   259,686/388,488 = 388,488/x
3. Step 3: Cross multiply
   259,686x = 388,488 × 388,488
4. Step 4: Simplify right side
   259,686x = 150,922,926,144
5. Step 5: Solve for x
   x = 150,922,926,144/259,686
6. Step 6: Final answer
   x = 581,174.67