Finding the Third Proportional to 13,978 and 21,147

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978 : 21,147 = 21,147 : x
2. Step 2: Convert to fraction form
   13,978/21,147 = 21,147/x
3. Step 3: Cross multiply
   13,978x = 21,147 × 21,147
4. Step 4: Simplify right side
   13,978x = 447,195,609
5. Step 5: Solve for x
   x = 447,195,609/13,978
6. Step 6: Final answer
   x = 31,992.82