Finding the Third Proportional to 131.38 and 285.38

Step by Step Solution

1. Step 1: Write the proportion equation
   131.38 : 285.38 = 285.38 : x
2. Step 2: Convert to fraction form
   131.38/285.38 = 285.38/x
3. Step 3: Cross multiply
   131.38x = 285.38 × 285.38
4. Step 4: Simplify right side
   131.38x = 81,438.89
5. Step 5: Solve for x
   x = 81,438.89/131.38
6. Step 6: Final answer
   x = 619.90