Finding the Third Proportional to 217,638 and 479,408

Step by Step Solution

1. Step 1: Write the proportion equation
   217,638 : 479,408 = 479,408 : x
2. Step 2: Convert to fraction form
   217,638/479,408 = 479,408/x
3. Step 3: Cross multiply
   217,638x = 479,408 × 479,408
4. Step 4: Simplify right side
   217,638x = 229,832,030,464
5. Step 5: Solve for x
   x = 229,832,030,464/217,638
6. Step 6: Final answer
   x = 1,056,028.96