Finding the Third Proportional to 417.78 and 905.31

Step by Step Solution

1. Step 1: Write the proportion equation
   417.78 : 905.31 = 905.31 : x
2. Step 2: Convert to fraction form
   417.78/905.31 = 905.31/x
3. Step 3: Cross multiply
   417.78x = 905.31 × 905.31
4. Step 4: Simplify right side
   417.78x = 819,590.72
5. Step 5: Solve for x
   x = 819,590.72/417.78
6. Step 6: Final answer
   x = 1,961.77