Finding the Third Proportional to 42.56 and 56.81

Step by Step Solution

1. Step 1: Write the proportion equation
   42.56 : 56.81 = 56.81 : x
2. Step 2: Convert to fraction form
   42.56/56.81 = 56.81/x
3. Step 3: Cross multiply
   42.56x = 56.81 × 56.81
4. Step 4: Simplify right side
   42.56x = 3,227.66
5. Step 5: Solve for x
   x = 3,227.66/42.56
6. Step 6: Final answer
   x = 75.83