Finding the Third Proportional to 89.30 and 138.23

Step by Step Solution

1. Step 1: Write the proportion equation
   89.30 : 138.23 = 138.23 : x
2. Step 2: Convert to fraction form
   89.30/138.23 = 138.23/x
3. Step 3: Cross multiply
   89.30x = 138.23 × 138.23
4. Step 4: Simplify right side
   89.30x = 19,108.74
5. Step 5: Solve for x
   x = 19,108.74/89.30
6. Step 6: Final answer
   x = 213.99