Finding the Third Proportional to 172.69 and 259.31

Step by Step Solution

1. Step 1: Write the proportion equation
   172.69 : 259.31 = 259.31 : x
2. Step 2: Convert to fraction form
   172.69/259.31 = 259.31/x
3. Step 3: Cross multiply
   172.69x = 259.31 × 259.31
4. Step 4: Simplify right side
   172.69x = 67,242.97
5. Step 5: Solve for x
   x = 67,242.97/172.69
6. Step 6: Final answer
   x = 389.39