Finding the Third Proportional to 21.73 and 55.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21.73 : 55.72 = 55.72 : x
2. Step 2: Convert to fraction form
   21.73/55.72 = 55.72/x
3. Step 3: Cross multiply
   21.73x = 55.72 × 55.72
4. Step 4: Simplify right side
   21.73x = 3,105.25
5. Step 5: Solve for x
   x = 3,105.25/21.73
6. Step 6: Final answer
   x = 142.88