Finding the Third Proportional to 12,399.75 and 21,888.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,399.75 : 21,888.56 = 21,888.56 : x
2. Step 2: Convert to fraction form
   12,399.75/21,888.56 = 21,888.56/x
3. Step 3: Cross multiply
   12,399.75x = 21,888.56 × 21,888.56
4. Step 4: Simplify right side
   12,399.75x = 479,109,168.32
5. Step 5: Solve for x
   x = 479,109,168.32/12,399.75
6. Step 6: Final answer
   x = 38,638.62