Finding the Third Proportional to 417.56 and 861.56

Step by Step Solution

1. Step 1: Write the proportion equation
   417.56 : 861.56 = 861.56 : x
2. Step 2: Convert to fraction form
   417.56/861.56 = 861.56/x
3. Step 3: Cross multiply
   417.56x = 861.56 × 861.56
4. Step 4: Simplify right side
   417.56x = 742,289.94
5. Step 5: Solve for x
   x = 742,289.94/417.56
6. Step 6: Final answer
   x = 1,777.67