Finding the Fourth Proportional to 21,342.83, 29,453.81 and 12,389.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,342.83 : 29,453.81 = 12,389.78 : x
2. Step 2: Convert to fraction form
   21,342.83/29,453.81 = 12,389.78/x
3. Step 3: Cross multiply
   21,342.83x = 29,453.81 × 12,389.78
4. Step 4: Simplify right side
   21,342.83x = 364,926,237.75
5. Step 5: Solve for x
   x = 364,926,237.75/21,342.83
6. Step 6: Final answer
   x = 17,098.31