Finding the Fourth Proportional to 11,986.20, 17,976.78 and 3,219

Step by Step Solution

1. Step 1: Write the proportion equation
   11,986.20 : 17,976.78 = 3,219 : x
2. Step 2: Convert to fraction form
   11,986.20/17,976.78 = 3,219/x
3. Step 3: Cross multiply
   11,986.20x = 17,976.78 × 3,219
4. Step 4: Simplify right side
   11,986.20x = 57,867,254.82
5. Step 5: Solve for x
   x = 57,867,254.82/11,986.20
6. Step 6: Final answer
   x = 4,827.82