Finding the Third Proportional to 421.45 and 654.96

Step by Step Solution

1. Step 1: Write the proportion equation
   421.45 : 654.96 = 654.96 : x
2. Step 2: Convert to fraction form
   421.45/654.96 = 654.96/x
3. Step 3: Cross multiply
   421.45x = 654.96 × 654.96
4. Step 4: Simplify right side
   421.45x = 428,973.83
5. Step 5: Solve for x
   x = 428,973.83/421.45
6. Step 6: Final answer
   x = 1,017.84