Finding the Third Proportional to 258,138 and 555,830

Step by Step Solution

1. Step 1: Write the proportion equation
   258,138 : 555,830 = 555,830 : x
2. Step 2: Convert to fraction form
   258,138/555,830 = 555,830/x
3. Step 3: Cross multiply
   258,138x = 555,830 × 555,830
4. Step 4: Simplify right side
   258,138x = 308,946,988,900
5. Step 5: Solve for x
   x = 308,946,988,900/258,138
6. Step 6: Final answer
   x = 1,196,828.78