Finding the Third Proportional to 30,978 and 67,212

Step by Step Solution

1. Step 1: Write the proportion equation
   30,978 : 67,212 = 67,212 : x
2. Step 2: Convert to fraction form
   30,978/67,212 = 67,212/x
3. Step 3: Cross multiply
   30,978x = 67,212 × 67,212
4. Step 4: Simplify right side
   30,978x = 4,517,452,944
5. Step 5: Solve for x
   x = 4,517,452,944/30,978
6. Step 6: Final answer
   x = 145,827.78