Finding the Third Proportional to 20.88 and 42.71

Step by Step Solution

1. Step 1: Write the proportion equation
   20.88 : 42.71 = 42.71 : x
2. Step 2: Convert to fraction form
   20.88/42.71 = 42.71/x
3. Step 3: Cross multiply
   20.88x = 42.71 × 42.71
4. Step 4: Simplify right side
   20.88x = 1,824.56
5. Step 5: Solve for x
   x = 1,824.56/20.88
6. Step 6: Final answer
   x = 87.37