Finding the Third Proportional to 399.38 and 535.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399.38 : 535.50 = 535.50 : x
2. Step 2: Convert to fraction form
   399.38/535.50 = 535.50/x
3. Step 3: Cross multiply
   399.38x = 535.50 × 535.50
4. Step 4: Simplify right side
   399.38x = 286,760.25
5. Step 5: Solve for x
   x = 286,760.25/399.38
6. Step 6: Final answer
   x = 718.02