Finding the Third Proportional to 89.75 and 139.25

Step by Step Solution

1. Step 1: Write the proportion equation
   89.75 : 139.25 = 139.25 : x
2. Step 2: Convert to fraction form
   89.75/139.25 = 139.25/x
3. Step 3: Cross multiply
   89.75x = 139.25 × 139.25
4. Step 4: Simplify right side
   89.75x = 19,390.56
5. Step 5: Solve for x
   x = 19,390.56/89.75
6. Step 6: Final answer
   x = 216.05