Finding the Third Proportional to 57.56 and 86.16

Step by Step Solution

1. Step 1: Write the proportion equation
   57.56 : 86.16 = 86.16 : x
2. Step 2: Convert to fraction form
   57.56/86.16 = 86.16/x
3. Step 3: Cross multiply
   57.56x = 86.16 × 86.16
4. Step 4: Simplify right side
   57.56x = 7,422.90
5. Step 5: Solve for x
   x = 7,422.90/57.56
6. Step 6: Final answer
   x = 128.95