Finding the Fourth Proportional to 13,198.86, 19,770.72 and 7,917.12

Step by Step Solution

1. Step 1: Write the proportion equation
   13,198.86 : 19,770.72 = 7,917.12 : x
2. Step 2: Convert to fraction form
   13,198.86/19,770.72 = 7,917.12/x
3. Step 3: Cross multiply
   13,198.86x = 19,770.72 × 7,917.12
4. Step 4: Simplify right side
   13,198.86x = 156,527,162.73
5. Step 5: Solve for x
   x = 156,527,162.73/13,198.86
6. Step 6: Final answer
   x = 11,859.14