Finding the Third Proportional to 399.66 and 856.27

Step by Step Solution

1. Step 1: Write the proportion equation
   399.66 : 856.27 = 856.27 : x
2. Step 2: Convert to fraction form
   399.66/856.27 = 856.27/x
3. Step 3: Cross multiply
   399.66x = 856.27 × 856.27
4. Step 4: Simplify right side
   399.66x = 733,190.82
5. Step 5: Solve for x
   x = 733,190.82/399.66
6. Step 6: Final answer
   x = 1,834.55