Finding the Third Proportional to 300,688 and 646,736

Step by Step Solution

1. Step 1: Write the proportion equation
   300,688 : 646,736 = 646,736 : x
2. Step 2: Convert to fraction form
   300,688/646,736 = 646,736/x
3. Step 3: Cross multiply
   300,688x = 646,736 × 646,736
4. Step 4: Simplify right side
   300,688x = 418,267,453,696
5. Step 5: Solve for x
   x = 418,267,453,696/300,688
6. Step 6: Final answer
   x = 1,391,034.74