Finding the Third Proportional to 31,831 and 69,139

Step by Step Solution

1. Step 1: Write the proportion equation
   31,831 : 69,139 = 69,139 : x
2. Step 2: Convert to fraction form
   31,831/69,139 = 69,139/x
3. Step 3: Cross multiply
   31,831x = 69,139 × 69,139
4. Step 4: Simplify right side
   31,831x = 4,780,201,321
5. Step 5: Solve for x
   x = 4,780,201,321/31,831
6. Step 6: Final answer
   x = 150,174.40