Finding the Fourth Proportional to 15,142.48, 20,892.42 and 9,091.15

Step by Step Solution

1. Step 1: Write the proportion equation
   15,142.48 : 20,892.42 = 9,091.15 : x
2. Step 2: Convert to fraction form
   15,142.48/20,892.42 = 9,091.15/x
3. Step 3: Cross multiply
   15,142.48x = 20,892.42 × 9,091.15
4. Step 4: Simplify right side
   15,142.48x = 189,936,019.62
5. Step 5: Solve for x
   x = 189,936,019.62/15,142.48
6. Step 6: Final answer
   x = 12,543.26