Finding the Third Proportional to 138.23 and 285.89

Step by Step Solution

1. Step 1: Write the proportion equation
   138.23 : 285.89 = 285.89 : x
2. Step 2: Convert to fraction form
   138.23/285.89 = 285.89/x
3. Step 3: Cross multiply
   138.23x = 285.89 × 285.89
4. Step 4: Simplify right side
   138.23x = 81,733.45
5. Step 5: Solve for x
   x = 81,733.45/138.23
6. Step 6: Final answer
   x = 591.27