Finding the Fourth Proportional to 21,891.39, 30,211.23 and 13,390.83

Step by Step Solution

1. Step 1: Write the proportion equation
   21,891.39 : 30,211.23 = 13,390.83 : x
2. Step 2: Convert to fraction form
   21,891.39/30,211.23 = 13,390.83/x
3. Step 3: Cross multiply
   21,891.39x = 30,211.23 × 13,390.83
4. Step 4: Simplify right side
   21,891.39x = 404,553,445.02
5. Step 5: Solve for x
   x = 404,553,445.02/21,891.39
6. Step 6: Final answer
   x = 18,480.03