Finding the Third Proportional to 31,400 and 68,740

Step by Step Solution

1. Step 1: Write the proportion equation
   31,400 : 68,740 = 68,740 : x
2. Step 2: Convert to fraction form
   31,400/68,740 = 68,740/x
3. Step 3: Cross multiply
   31,400x = 68,740 × 68,740
4. Step 4: Simplify right side
   31,400x = 4,725,187,600
5. Step 5: Solve for x
   x = 4,725,187,600/31,400
6. Step 6: Final answer
   x = 150,483.68