Finding the Fourth Proportional to 12,991.86, 17,928.84 and 7,326.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,991.86 : 17,928.84 = 7,326.72 : x
2. Step 2: Convert to fraction form
   12,991.86/17,928.84 = 7,326.72/x
3. Step 3: Cross multiply
   12,991.86x = 17,928.84 × 7,326.72
4. Step 4: Simplify right side
   12,991.86x = 131,359,618.08
5. Step 5: Solve for x
   x = 131,359,618.08/12,991.86
6. Step 6: Final answer
   x = 10,110.92