Finding the Third Proportional to 363,388 and 509,216

Step by Step Solution

1. Step 1: Write the proportion equation
   363,388 : 509,216 = 509,216 : x
2. Step 2: Convert to fraction form
   363,388/509,216 = 509,216/x
3. Step 3: Cross multiply
   363,388x = 509,216 × 509,216
4. Step 4: Simplify right side
   363,388x = 259,300,934,656
5. Step 5: Solve for x
   x = 259,300,934,656/363,388
6. Step 6: Final answer
   x = 713,564.94