Finding the Third Proportional to 391.69 and 729.38

Step by Step Solution

1. Step 1: Write the proportion equation
   391.69 : 729.38 = 729.38 : x
2. Step 2: Convert to fraction form
   391.69/729.38 = 729.38/x
3. Step 3: Cross multiply
   391.69x = 729.38 × 729.38
4. Step 4: Simplify right side
   391.69x = 531,987.89
5. Step 5: Solve for x
   x = 531,987.89/391.69
6. Step 6: Final answer
   x = 1,358.19