Finding the Third Proportional to 313,870 and 686,054

Step by Step Solution

1. Step 1: Write the proportion equation
   313,870 : 686,054 = 686,054 : x
2. Step 2: Convert to fraction form
   313,870/686,054 = 686,054/x
3. Step 3: Cross multiply
   313,870x = 686,054 × 686,054
4. Step 4: Simplify right side
   313,870x = 470,670,090,916
5. Step 5: Solve for x
   x = 470,670,090,916/313,870
6. Step 6: Final answer
   x = 1,499,570.18