Finding the Third Proportional to 120,819 and 259,131

Step by Step Solution

1. Step 1: Write the proportion equation
   120,819 : 259,131 = 259,131 : x
2. Step 2: Convert to fraction form
   120,819/259,131 = 259,131/x
3. Step 3: Cross multiply
   120,819x = 259,131 × 259,131
4. Step 4: Simplify right side
   120,819x = 67,148,875,161
5. Step 5: Solve for x
   x = 67,148,875,161/120,819
6. Step 6: Final answer
   x = 555,780.76