Finding the Third Proportional to 138,515 and 298,900

Step by Step Solution

1. Step 1: Write the proportion equation
   138,515 : 298,900 = 298,900 : x
2. Step 2: Convert to fraction form
   138,515/298,900 = 298,900/x
3. Step 3: Cross multiply
   138,515x = 298,900 × 298,900
4. Step 4: Simplify right side
   138,515x = 89,341,210,000
5. Step 5: Solve for x
   x = 89,341,210,000/138,515
6. Step 6: Final answer
   x = 644,993.03