Finding the Third Proportional to 31.09 and 67.87

Step by Step Solution

1. Step 1: Write the proportion equation
   31.09 : 67.87 = 67.87 : x
2. Step 2: Convert to fraction form
   31.09/67.87 = 67.87/x
3. Step 3: Cross multiply
   31.09x = 67.87 × 67.87
4. Step 4: Simplify right side
   31.09x = 4,606.22
5. Step 5: Solve for x
   x = 4,606.22/31.09
6. Step 6: Final answer
   x = 148.17