Finding the Third Proportional to 172.13 and 190.69

Step by Step Solution

1. Step 1: Write the proportion equation
   172.13 : 190.69 = 190.69 : x
2. Step 2: Convert to fraction form
   172.13/190.69 = 190.69/x
3. Step 3: Cross multiply
   172.13x = 190.69 × 190.69
4. Step 4: Simplify right side
   172.13x = 36,361.72
5. Step 5: Solve for x
   x = 36,361.72/172.13
6. Step 6: Final answer
   x = 211.25