Finding the Third Proportional to 328.78 and 723.38

Step by Step Solution

1. Step 1: Write the proportion equation
   328.78 : 723.38 = 723.38 : x
2. Step 2: Convert to fraction form
   328.78/723.38 = 723.38/x
3. Step 3: Cross multiply
   328.78x = 723.38 × 723.38
4. Step 4: Simplify right side
   328.78x = 523,271.39
5. Step 5: Solve for x
   x = 523,271.39/328.78
6. Step 6: Final answer
   x = 1,591.55