Finding the Third Proportional to 218,696 and 478,240

Step by Step Solution

1. Step 1: Write the proportion equation
   218,696 : 478,240 = 478,240 : x
2. Step 2: Convert to fraction form
   218,696/478,240 = 478,240/x
3. Step 3: Cross multiply
   218,696x = 478,240 × 478,240
4. Step 4: Simplify right side
   218,696x = 228,713,497,600
5. Step 5: Solve for x
   x = 228,713,497,600/218,696
6. Step 6: Final answer
   x = 1,045,805.58