Finding the Third Proportional to 12,978 and 19,447

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978 : 19,447 = 19,447 : x
2. Step 2: Convert to fraction form
   12,978/19,447 = 19,447/x
3. Step 3: Cross multiply
   12,978x = 19,447 × 19,447
4. Step 4: Simplify right side
   12,978x = 378,185,809
5. Step 5: Solve for x
   x = 378,185,809/12,978
6. Step 6: Final answer
   x = 29,140.53