Finding the Third Proportional to 172,800 and 259,200

Step by Step Solution

1. Step 1: Write the proportion equation
   172,800 : 259,200 = 259,200 : x
2. Step 2: Convert to fraction form
   172,800/259,200 = 259,200/x
3. Step 3: Cross multiply
   172,800x = 259,200 × 259,200
4. Step 4: Simplify right side
   172,800x = 67,184,640,000
5. Step 5: Solve for x
   x = 67,184,640,000/172,800
6. Step 6: Final answer
   x = 388,800