Finding the Fourth Proportional to 21,915.73, 30,245.91 and 13,423.39

Step by Step Solution

1. Step 1: Write the proportion equation
   21,915.73 : 30,245.91 = 13,423.39 : x
2. Step 2: Convert to fraction form
   21,915.73/30,245.91 = 13,423.39/x
3. Step 3: Cross multiply
   21,915.73x = 30,245.91 × 13,423.39
4. Step 4: Simplify right side
   21,915.73x = 406,002,519.88
5. Step 5: Solve for x
   x = 406,002,519.88/21,915.73
6. Step 6: Final answer
   x = 18,525.62