Finding the Third Proportional to 39.87 and 86.48

Step by Step Solution

1. Step 1: Write the proportion equation
   39.87 : 86.48 = 86.48 : x
2. Step 2: Convert to fraction form
   39.87/86.48 = 86.48/x
3. Step 3: Cross multiply
   39.87x = 86.48 × 86.48
4. Step 4: Simplify right side
   39.87x = 7,479.55
5. Step 5: Solve for x
   x = 7,479.55/39.87
6. Step 6: Final answer
   x = 187.61