Finding the Third Proportional to 275,556 and 390,018

Step by Step Solution

1. Step 1: Write the proportion equation
   275,556 : 390,018 = 390,018 : x
2. Step 2: Convert to fraction form
   275,556/390,018 = 390,018/x
3. Step 3: Cross multiply
   275,556x = 390,018 × 390,018
4. Step 4: Simplify right side
   275,556x = 152,114,040,324
5. Step 5: Solve for x
   x = 152,114,040,324/275,556
6. Step 6: Final answer
   x = 552,025.87