Finding the Third Proportional to 263,456 and 390,610

Step by Step Solution

1. Step 1: Write the proportion equation
   263,456 : 390,610 = 390,610 : x
2. Step 2: Convert to fraction form
   263,456/390,610 = 390,610/x
3. Step 3: Cross multiply
   263,456x = 390,610 × 390,610
4. Step 4: Simplify right side
   263,456x = 152,576,172,100
5. Step 5: Solve for x
   x = 152,576,172,100/263,456
6. Step 6: Final answer
   x = 579,133.41