Finding the Fourth Proportional to 9,681.16, 13,359.42 and 5,431.90

Step by Step Solution

1. Step 1: Write the proportion equation
   9,681.16 : 13,359.42 = 5,431.90 : x
2. Step 2: Convert to fraction form
   9,681.16/13,359.42 = 5,431.90/x
3. Step 3: Cross multiply
   9,681.16x = 13,359.42 × 5,431.90
4. Step 4: Simplify right side
   9,681.16x = 72,567,033.50
5. Step 5: Solve for x
   x = 72,567,033.50/9,681.16
6. Step 6: Final answer
   x = 7,495.70