Finding the Third Proportional to 140,870 and 309,388

Step by Step Solution

1. Step 1: Write the proportion equation
   140,870 : 309,388 = 309,388 : x
2. Step 2: Convert to fraction form
   140,870/309,388 = 309,388/x
3. Step 3: Cross multiply
   140,870x = 309,388 × 309,388
4. Step 4: Simplify right side
   140,870x = 95,720,934,544
5. Step 5: Solve for x
   x = 95,720,934,544/140,870
6. Step 6: Final answer
   x = 679,498.36