Finding the Third Proportional to 81.42 and 105.61

Step by Step Solution

1. Step 1: Write the proportion equation
   81.42 : 105.61 = 105.61 : x
2. Step 2: Convert to fraction form
   81.42/105.61 = 105.61/x
3. Step 3: Cross multiply
   81.42x = 105.61 × 105.61
4. Step 4: Simplify right side
   81.42x = 11,153.34
5. Step 5: Solve for x
   x = 11,153.34/81.42
6. Step 6: Final answer
   x = 136.98