Finding the Third Proportional to 81.56 and 178.31

Step by Step Solution

1. Step 1: Write the proportion equation
   81.56 : 178.31 = 178.31 : x
2. Step 2: Convert to fraction form
   81.56/178.31 = 178.31/x
3. Step 3: Cross multiply
   81.56x = 178.31 × 178.31
4. Step 4: Simplify right side
   81.56x = 31,795.35
5. Step 5: Solve for x
   x = 31,795.35/81.56
6. Step 6: Final answer
   x = 389.83