Finding the Third Proportional to 258,648 and 388,328

Step by Step Solution

1. Step 1: Write the proportion equation
   258,648 : 388,328 = 388,328 : x
2. Step 2: Convert to fraction form
   258,648/388,328 = 388,328/x
3. Step 3: Cross multiply
   258,648x = 388,328 × 388,328
4. Step 4: Simplify right side
   258,648x = 150,798,635,584
5. Step 5: Solve for x
   x = 150,798,635,584/258,648
6. Step 6: Final answer
   x = 583,026.49