Finding the Third Proportional to 172.88 and 381.56

Step by Step Solution

1. Step 1: Write the proportion equation
   172.88 : 381.56 = 381.56 : x
2. Step 2: Convert to fraction form
   172.88/381.56 = 381.56/x
3. Step 3: Cross multiply
   172.88x = 381.56 × 381.56
4. Step 4: Simplify right side
   172.88x = 145,589.94
5. Step 5: Solve for x
   x = 145,589.94/172.88
6. Step 6: Final answer
   x = 842.17