Finding the Fourth Proportional to 12,919.72, 17,831.17 and 7,886.87

Step by Step Solution

1. Step 1: Write the proportion equation
   12,919.72 : 17,831.17 = 7,886.87 : x
2. Step 2: Convert to fraction form
   12,919.72/17,831.17 = 7,886.87/x
3. Step 3: Cross multiply
   12,919.72x = 17,831.17 × 7,886.87
4. Step 4: Simplify right side
   12,919.72x = 140,632,144.60
5. Step 5: Solve for x
   x = 140,632,144.60/12,919.72
6. Step 6: Final answer
   x = 10,885.07