Finding the Fourth Proportional to 9,897.57, 13,658.55 and 5,421.31

Step by Step Solution

1. Step 1: Write the proportion equation
   9,897.57 : 13,658.55 = 5,421.31 : x
2. Step 2: Convert to fraction form
   9,897.57/13,658.55 = 5,421.31/x
3. Step 3: Cross multiply
   9,897.57x = 13,658.55 × 5,421.31
4. Step 4: Simplify right side
   9,897.57x = 74,047,233.70
5. Step 5: Solve for x
   x = 74,047,233.70/9,897.57
6. Step 6: Final answer
   x = 7,481.35