Finding the Third Proportional to 20.88 and 53.94

Step by Step Solution

1. Step 1: Write the proportion equation
   20.88 : 53.94 = 53.94 : x
2. Step 2: Convert to fraction form
   20.88/53.94 = 53.94/x
3. Step 3: Cross multiply
   20.88x = 53.94 × 53.94
4. Step 4: Simplify right side
   20.88x = 2,909.25
5. Step 5: Solve for x
   x = 2,909.25/20.88
6. Step 6: Final answer
   x = 139.37