Finding the Third Proportional to 399.94 and 538.59

Step by Step Solution

1. Step 1: Write the proportion equation
   399.94 : 538.59 = 538.59 : x
2. Step 2: Convert to fraction form
   399.94/538.59 = 538.59/x
3. Step 3: Cross multiply
   399.94x = 538.59 × 538.59
4. Step 4: Simplify right side
   399.94x = 290,083.23
5. Step 5: Solve for x
   x = 290,083.23/399.94
6. Step 6: Final answer
   x = 725.32