Finding the Third Proportional to 254,928 and 404,890

Step by Step Solution

1. Step 1: Write the proportion equation
   254,928 : 404,890 = 404,890 : x
2. Step 2: Convert to fraction form
   254,928/404,890 = 404,890/x
3. Step 3: Cross multiply
   254,928x = 404,890 × 404,890
4. Step 4: Simplify right side
   254,928x = 163,935,912,100
5. Step 5: Solve for x
   x = 163,935,912,100/254,928
6. Step 6: Final answer
   x = 643,067.50