Finding the Third Proportional to 168,870 and 258,921

Step by Step Solution

1. Step 1: Write the proportion equation
   168,870 : 258,921 = 258,921 : x
2. Step 2: Convert to fraction form
   168,870/258,921 = 258,921/x
3. Step 3: Cross multiply
   168,870x = 258,921 × 258,921
4. Step 4: Simplify right side
   168,870x = 67,040,084,241
5. Step 5: Solve for x
   x = 67,040,084,241/168,870
6. Step 6: Final answer
   x = 396,992.27