Finding the Third Proportional to 39.50 and 86.50

Step by Step Solution

1. Step 1: Write the proportion equation
   39.50 : 86.50 = 86.50 : x
2. Step 2: Convert to fraction form
   39.50/86.50 = 86.50/x
3. Step 3: Cross multiply
   39.50x = 86.50 × 86.50
4. Step 4: Simplify right side
   39.50x = 7,482.25
5. Step 5: Solve for x
   x = 7,482.25/39.50
6. Step 6: Final answer
   x = 189.42