Finding the Third Proportional to 21.38 and 41.69

Step by Step Solution

1. Step 1: Write the proportion equation
   21.38 : 41.69 = 41.69 : x
2. Step 2: Convert to fraction form
   21.38/41.69 = 41.69/x
3. Step 3: Cross multiply
   21.38x = 41.69 × 41.69
4. Step 4: Simplify right side
   21.38x = 1,737.85
5. Step 5: Solve for x
   x = 1,737.85/21.38
6. Step 6: Final answer
   x = 81.30