Finding the Third Proportional to 30.85 and 65.50

Step by Step Solution

1. Step 1: Write the proportion equation
   30.85 : 65.50 = 65.50 : x
2. Step 2: Convert to fraction form
   30.85/65.50 = 65.50/x
3. Step 3: Cross multiply
   30.85x = 65.50 × 65.50
4. Step 4: Simplify right side
   30.85x = 4,289.74
5. Step 5: Solve for x
   x = 4,289.74/30.85
6. Step 6: Final answer
   x = 139.05