Finding the Third Proportional to 53.75 and 86.56

Step by Step Solution

1. Step 1: Write the proportion equation
   53.75 : 86.56 = 86.56 : x
2. Step 2: Convert to fraction form
   53.75/86.56 = 86.56/x
3. Step 3: Cross multiply
   53.75x = 86.56 × 86.56
4. Step 4: Simplify right side
   53.75x = 7,493.07
5. Step 5: Solve for x
   x = 7,493.07/53.75
6. Step 6: Final answer
   x = 139.41