Finding the Fourth Proportional to 21,013, 31,498.23 and 13,622.15

Step by Step Solution

1. Step 1: Write the proportion equation
   21,013 : 31,498.23 = 13,622.15 : x
2. Step 2: Convert to fraction form
   21,013/31,498.23 = 13,622.15/x
3. Step 3: Cross multiply
   21,013x = 31,498.23 × 13,622.15
4. Step 4: Simplify right side
   21,013x = 429,073,613.79
5. Step 5: Solve for x
   x = 429,073,613.79/21,013
6. Step 6: Final answer
   x = 20,419.44