Finding the Third Proportional to 86.50 and 134.50

Step by Step Solution

1. Step 1: Write the proportion equation
   86.50 : 134.50 = 134.50 : x
2. Step 2: Convert to fraction form
   86.50/134.50 = 134.50/x
3. Step 3: Cross multiply
   86.50x = 134.50 × 134.50
4. Step 4: Simplify right side
   86.50x = 18,090.25
5. Step 5: Solve for x
   x = 18,090.25/86.50
6. Step 6: Final answer
   x = 209.14