Finding the Fourth Proportional to 21,616.56, 29,811 and 13,644.96

Step by Step Solution

1. Step 1: Write the proportion equation
   21,616.56 : 29,811 = 13,644.96 : x
2. Step 2: Convert to fraction form
   21,616.56/29,811 = 13,644.96/x
3. Step 3: Cross multiply
   21,616.56x = 29,811 × 13,644.96
4. Step 4: Simplify right side
   21,616.56x = 406,769,902.56
5. Step 5: Solve for x
   x = 406,769,902.56/21,616.56
6. Step 6: Final answer
   x = 18,817.51