Finding the Fourth Proportional to 12,648.78, 18,972.91 and 4,215.89

Step by Step Solution

1. Step 1: Write the proportion equation
   12,648.78 : 18,972.91 = 4,215.89 : x
2. Step 2: Convert to fraction form
   12,648.78/18,972.91 = 4,215.89/x
3. Step 3: Cross multiply
   12,648.78x = 18,972.91 × 4,215.89
4. Step 4: Simplify right side
   12,648.78x = 79,987,781.57
5. Step 5: Solve for x
   x = 79,987,781.57/12,648.78
6. Step 6: Final answer
   x = 6,323.76