Finding the Fourth Proportional to 9,160.18, 12,639.69 and 5,181.21

Step by Step Solution

1. Step 1: Write the proportion equation
   9,160.18 : 12,639.69 = 5,181.21 : x
2. Step 2: Convert to fraction form
   9,160.18/12,639.69 = 5,181.21/x
3. Step 3: Cross multiply
   9,160.18x = 12,639.69 × 5,181.21
4. Step 4: Simplify right side
   9,160.18x = 65,488,888.22
5. Step 5: Solve for x
   x = 65,488,888.22/9,160.18
6. Step 6: Final answer
   x = 7,149.30