Finding the Third Proportional to 6,718 and 11,978

Step by Step Solution

1. Step 1: Write the proportion equation
   6,718 : 11,978 = 11,978 : x
2. Step 2: Convert to fraction form
   6,718/11,978 = 11,978/x
3. Step 3: Cross multiply
   6,718x = 11,978 × 11,978
4. Step 4: Simplify right side
   6,718x = 143,472,484
5. Step 5: Solve for x
   x = 143,472,484/6,718
6. Step 6: Final answer
   x = 21,356.43