Finding the Third Proportional to 261.50 and 401.25

Step by Step Solution

1. Step 1: Write the proportion equation
   261.50 : 401.25 = 401.25 : x
2. Step 2: Convert to fraction form
   261.50/401.25 = 401.25/x
3. Step 3: Cross multiply
   261.50x = 401.25 × 401.25
4. Step 4: Simplify right side
   261.50x = 161,001.56
5. Step 5: Solve for x
   x = 161,001.56/261.50
6. Step 6: Final answer
   x = 615.68