Finding the Third Proportional to 83.81 and 128.53

Step by Step Solution

1. Step 1: Write the proportion equation
   83.81 : 128.53 = 128.53 : x
2. Step 2: Convert to fraction form
   83.81/128.53 = 128.53/x
3. Step 3: Cross multiply
   83.81x = 128.53 × 128.53
4. Step 4: Simplify right side
   83.81x = 16,520.28
5. Step 5: Solve for x
   x = 16,520.28/83.81
6. Step 6: Final answer
   x = 197.11