Finding the Third Proportional to 18.56 and 38.81

Step by Step Solution

1. Step 1: Write the proportion equation
   18.56 : 38.81 = 38.81 : x
2. Step 2: Convert to fraction form
   18.56/38.81 = 38.81/x
3. Step 3: Cross multiply
   18.56x = 38.81 × 38.81
4. Step 4: Simplify right side
   18.56x = 1,506.41
5. Step 5: Solve for x
   x = 1,506.41/18.56
6. Step 6: Final answer
   x = 81.15