Finding the Fourth Proportional to 9,120.89, 12,585.83 and 5,142.17

Step by Step Solution

1. Step 1: Write the proportion equation
   9,120.89 : 12,585.83 = 5,142.17 : x
2. Step 2: Convert to fraction form
   9,120.89/12,585.83 = 5,142.17/x
3. Step 3: Cross multiply
   9,120.89x = 12,585.83 × 5,142.17
4. Step 4: Simplify right side
   9,120.89x = 64,718,388.81
5. Step 5: Solve for x
   x = 64,718,388.81/9,120.89
6. Step 6: Final answer
   x = 7,095.63