Finding the Fourth Proportional to 21,013.98, 31,522.05 and 5,431.74

Step by Step Solution

1. Step 1: Write the proportion equation
   21,013.98 : 31,522.05 = 5,431.74 : x
2. Step 2: Convert to fraction form
   21,013.98/31,522.05 = 5,431.74/x
3. Step 3: Cross multiply
   21,013.98x = 31,522.05 × 5,431.74
4. Step 4: Simplify right side
   21,013.98x = 171,219,579.87
5. Step 5: Solve for x
   x = 171,219,579.87/21,013.98
6. Step 6: Final answer
   x = 8,147.89