Finding the Third Proportional to 31,780 and 69,800

Step by Step Solution

1. Step 1: Write the proportion equation
   31,780 : 69,800 = 69,800 : x
2. Step 2: Convert to fraction form
   31,780/69,800 = 69,800/x
3. Step 3: Cross multiply
   31,780x = 69,800 × 69,800
4. Step 4: Simplify right side
   31,780x = 4,872,040,000
5. Step 5: Solve for x
   x = 4,872,040,000/31,780
6. Step 6: Final answer
   x = 153,305.22