Finding the Third Proportional to 89.19 and 138.06

Step by Step Solution

1. Step 1: Write the proportion equation
   89.19 : 138.06 = 138.06 : x
2. Step 2: Convert to fraction form
   89.19/138.06 = 138.06/x
3. Step 3: Cross multiply
   89.19x = 138.06 × 138.06
4. Step 4: Simplify right side
   89.19x = 19,061.25
5. Step 5: Solve for x
   x = 19,061.25/89.19
6. Step 6: Final answer
   x = 213.72