Finding the Third Proportional to 300,068 and 640,328

Step by Step Solution

1. Step 1: Write the proportion equation
   300,068 : 640,328 = 640,328 : x
2. Step 2: Convert to fraction form
   300,068/640,328 = 640,328/x
3. Step 3: Cross multiply
   300,068x = 640,328 × 640,328
4. Step 4: Simplify right side
   300,068x = 410,019,947,584
5. Step 5: Solve for x
   x = 410,019,947,584/300,068
6. Step 6: Final answer
   x = 1,366,423.44