Finding the Fourth Proportional to 21,816.45, 30,105.91 and 13,332.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,816.45 : 30,105.91 = 13,332.78 : x
2. Step 2: Convert to fraction form
   21,816.45/30,105.91 = 13,332.78/x
3. Step 3: Cross multiply
   21,816.45x = 30,105.91 × 13,332.78
4. Step 4: Simplify right side
   21,816.45x = 401,395,474.73
5. Step 5: Solve for x
   x = 401,395,474.73/21,816.45
6. Step 6: Final answer
   x = 18,398.75