Finding the Third Proportional to 312,264 and 686,736

Step by Step Solution

1. Step 1: Write the proportion equation
   312,264 : 686,736 = 686,736 : x
2. Step 2: Convert to fraction form
   312,264/686,736 = 686,736/x
3. Step 3: Cross multiply
   312,264x = 686,736 × 686,736
4. Step 4: Simplify right side
   312,264x = 471,606,333,696
5. Step 5: Solve for x
   x = 471,606,333,696/312,264
6. Step 6: Final answer
   x = 1,510,280.83