Finding the Fourth Proportional to 21,141.56, 29,175.28 and 12,189.02

Step by Step Solution

1. Step 1: Write the proportion equation
   21,141.56 : 29,175.28 = 12,189.02 : x
2. Step 2: Convert to fraction form
   21,141.56/29,175.28 = 12,189.02/x
3. Step 3: Cross multiply
   21,141.56x = 29,175.28 × 12,189.02
4. Step 4: Simplify right side
   21,141.56x = 355,618,071.43
5. Step 5: Solve for x
   x = 355,618,071.43/21,141.56
6. Step 6: Final answer
   x = 16,820.81