Finding the Third Proportional to 142.83 and 213.31

Step by Step Solution

1. Step 1: Write the proportion equation
   142.83 : 213.31 = 213.31 : x
2. Step 2: Convert to fraction form
   142.83/213.31 = 213.31/x
3. Step 3: Cross multiply
   142.83x = 213.31 × 213.31
4. Step 4: Simplify right side
   142.83x = 45,499.98
5. Step 5: Solve for x
   x = 45,499.98/142.83
6. Step 6: Final answer
   x = 318.57