Finding the Fourth Proportional to 21,123.56, 29,169.87 and 13,583

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.56 : 29,169.87 = 13,583 : x
2. Step 2: Convert to fraction form
   21,123.56/29,169.87 = 13,583/x
3. Step 3: Cross multiply
   21,123.56x = 29,169.87 × 13,583
4. Step 4: Simplify right side
   21,123.56x = 396,214,344.21
5. Step 5: Solve for x
   x = 396,214,344.21/21,123.56
6. Step 6: Final answer
   x = 18,756.99