Finding the Third Proportional to 120,800 and 258,222

Step by Step Solution

1. Step 1: Write the proportion equation
   120,800 : 258,222 = 258,222 : x
2. Step 2: Convert to fraction form
   120,800/258,222 = 258,222/x
3. Step 3: Cross multiply
   120,800x = 258,222 × 258,222
4. Step 4: Simplify right side
   120,800x = 66,678,601,284
5. Step 5: Solve for x
   x = 66,678,601,284/120,800
6. Step 6: Final answer
   x = 551,975.18