Finding the Third Proportional to 481.88 and 642.56

Step by Step Solution

1. Step 1: Write the proportion equation
   481.88 : 642.56 = 642.56 : x
2. Step 2: Convert to fraction form
   481.88/642.56 = 642.56/x
3. Step 3: Cross multiply
   481.88x = 642.56 × 642.56
4. Step 4: Simplify right side
   481.88x = 412,886.57
5. Step 5: Solve for x
   x = 412,886.57/481.88
6. Step 6: Final answer
   x = 856.83