Finding the Third Proportional to 89.72 and 140.69

Step by Step Solution

1. Step 1: Write the proportion equation
   89.72 : 140.69 = 140.69 : x
2. Step 2: Convert to fraction form
   89.72/140.69 = 140.69/x
3. Step 3: Cross multiply
   89.72x = 140.69 × 140.69
4. Step 4: Simplify right side
   89.72x = 19,792.97
5. Step 5: Solve for x
   x = 19,792.97/89.72
6. Step 6: Final answer
   x = 220.61