Finding the Third Proportional to 254,928 and 405,012

Step by Step Solution

1. Step 1: Write the proportion equation
   254,928 : 405,012 = 405,012 : x
2. Step 2: Convert to fraction form
   254,928/405,012 = 405,012/x
3. Step 3: Cross multiply
   254,928x = 405,012 × 405,012
4. Step 4: Simplify right side
   254,928x = 164,034,720,144
5. Step 5: Solve for x
   x = 164,034,720,144/254,928
6. Step 6: Final answer
   x = 643,455.09