Finding the Third Proportional to 138,790 and 298,630

Step by Step Solution

1. Step 1: Write the proportion equation
   138,790 : 298,630 = 298,630 : x
2. Step 2: Convert to fraction form
   138,790/298,630 = 298,630/x
3. Step 3: Cross multiply
   138,790x = 298,630 × 298,630
4. Step 4: Simplify right side
   138,790x = 89,179,876,900
5. Step 5: Solve for x
   x = 89,179,876,900/138,790
6. Step 6: Final answer
   x = 642,552.61