Finding the Fourth Proportional to 9,120.11, 12,585.37 and 5,142.05

Step by Step Solution

1. Step 1: Write the proportion equation
   9,120.11 : 12,585.37 = 5,142.05 : x
2. Step 2: Convert to fraction form
   9,120.11/12,585.37 = 5,142.05/x
3. Step 3: Cross multiply
   9,120.11x = 12,585.37 × 5,142.05
4. Step 4: Simplify right side
   9,120.11x = 64,714,601.81
5. Step 5: Solve for x
   x = 64,714,601.81/9,120.11
6. Step 6: Final answer
   x = 7,095.81