Finding the Third Proportional to 218,688 and 478,368

Step by Step Solution

1. Step 1: Write the proportion equation
   218,688 : 478,368 = 478,368 : x
2. Step 2: Convert to fraction form
   218,688/478,368 = 478,368/x
3. Step 3: Cross multiply
   218,688x = 478,368 × 478,368
4. Step 4: Simplify right side
   218,688x = 228,835,943,424
5. Step 5: Solve for x
   x = 228,835,943,424/218,688
6. Step 6: Final answer
   x = 1,046,403.75