Finding the Fourth Proportional to 21,288.22, 29,375.06 and 12,789.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,288.22 : 29,375.06 = 12,789.09 : x
2. Step 2: Convert to fraction form
   21,288.22/29,375.06 = 12,789.09/x
3. Step 3: Cross multiply
   21,288.22x = 29,375.06 × 12,789.09
4. Step 4: Simplify right side
   21,288.22x = 375,680,222.15
5. Step 5: Solve for x
   x = 375,680,222.15/21,288.22
6. Step 6: Final answer
   x = 17,647.33