Finding the Third Proportional to 31,687 and 67,409.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,687 : 67,409.50 = 67,409.50 : x
2. Step 2: Convert to fraction form
   31,687/67,409.50 = 67,409.50/x
3. Step 3: Cross multiply
   31,687x = 67,409.50 × 67,409.50
4. Step 4: Simplify right side
   31,687x = 4,544,040,690.25
5. Step 5: Solve for x
   x = 4,544,040,690.25/31,687
6. Step 6: Final answer
   x = 143,403.94