Finding the Third Proportional to 89.86 and 139.54

Step by Step Solution

1. Step 1: Write the proportion equation
   89.86 : 139.54 = 139.54 : x
2. Step 2: Convert to fraction form
   89.86/139.54 = 139.54/x
3. Step 3: Cross multiply
   89.86x = 139.54 × 139.54
4. Step 4: Simplify right side
   89.86x = 19,470.06
5. Step 5: Solve for x
   x = 19,470.06/89.86
6. Step 6: Final answer
   x = 216.67