Finding the Third Proportional to 12,039.75 and 15,978.38

Step by Step Solution

1. Step 1: Write the proportion equation
   12,039.75 : 15,978.38 = 15,978.38 : x
2. Step 2: Convert to fraction form
   12,039.75/15,978.38 = 15,978.38/x
3. Step 3: Cross multiply
   12,039.75x = 15,978.38 × 15,978.38
4. Step 4: Simplify right side
   12,039.75x = 255,308,467.64
5. Step 5: Solve for x
   x = 255,308,467.64/12,039.75
6. Step 6: Final answer
   x = 21,205.46