Finding the Third Proportional to 172.13 and 400.31

Step by Step Solution

1. Step 1: Write the proportion equation
   172.13 : 400.31 = 400.31 : x
2. Step 2: Convert to fraction form
   172.13/400.31 = 400.31/x
3. Step 3: Cross multiply
   172.13x = 400.31 × 400.31
4. Step 4: Simplify right side
   172.13x = 160,250.10
5. Step 5: Solve for x
   x = 160,250.10/172.13
6. Step 6: Final answer
   x = 931.01