Finding the Third Proportional to 388,864 and 609,216

Step by Step Solution

1. Step 1: Write the proportion equation
   388,864 : 609,216 = 609,216 : x
2. Step 2: Convert to fraction form
   388,864/609,216 = 609,216/x
3. Step 3: Cross multiply
   388,864x = 609,216 × 609,216
4. Step 4: Simplify right side
   388,864x = 371,144,134,656
5. Step 5: Solve for x
   x = 371,144,134,656/388,864
6. Step 6: Final answer
   x = 954,431.72