Finding the Third Proportional to 172.31 and 312.56

Step by Step Solution

1. Step 1: Write the proportion equation
   172.31 : 312.56 = 312.56 : x
2. Step 2: Convert to fraction form
   172.31/312.56 = 312.56/x
3. Step 3: Cross multiply
   172.31x = 312.56 × 312.56
4. Step 4: Simplify right side
   172.31x = 97,695.32
5. Step 5: Solve for x
   x = 97,695.32/172.31
6. Step 6: Final answer
   x = 566.97