Finding the Fourth Proportional to 21,189.88, 31,781.58 and 5,608.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,189.88 : 31,781.58 = 5,608.72 : x
2. Step 2: Convert to fraction form
   21,189.88/31,781.58 = 5,608.72/x
3. Step 3: Cross multiply
   21,189.88x = 31,781.58 × 5,608.72
4. Step 4: Simplify right side
   21,189.88x = 178,253,983.38
5. Step 5: Solve for x
   x = 178,253,983.38/21,189.88
6. Step 6: Final answer
   x = 8,412.22