Finding the Third Proportional to 155,678 and 245,990

Step by Step Solution

1. Step 1: Write the proportion equation
   155,678 : 245,990 = 245,990 : x
2. Step 2: Convert to fraction form
   155,678/245,990 = 245,990/x
3. Step 3: Cross multiply
   155,678x = 245,990 × 245,990
4. Step 4: Simplify right side
   155,678x = 60,511,080,100
5. Step 5: Solve for x
   x = 60,511,080,100/155,678
6. Step 6: Final answer
   x = 388,693.84