Finding the Fourth Proportional to 12,816.42, 17,686.20 and 7,150.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,816.42 : 17,686.20 = 7,150.86 : x
2. Step 2: Convert to fraction form
   12,816.42/17,686.20 = 7,150.86/x
3. Step 3: Cross multiply
   12,816.42x = 17,686.20 × 7,150.86
4. Step 4: Simplify right side
   12,816.42x = 126,471,540.13
5. Step 5: Solve for x
   x = 126,471,540.13/12,816.42
6. Step 6: Final answer
   x = 9,867.93