Finding the Third Proportional to 120,816 and 259,128

Step by Step Solution

1. Step 1: Write the proportion equation
   120,816 : 259,128 = 259,128 : x
2. Step 2: Convert to fraction form
   120,816/259,128 = 259,128/x
3. Step 3: Cross multiply
   120,816x = 259,128 × 259,128
4. Step 4: Simplify right side
   120,816x = 67,147,320,384
5. Step 5: Solve for x
   x = 67,147,320,384/120,816
6. Step 6: Final answer
   x = 555,781.69