Finding the Fourth Proportional to 11,986.81, 17,978.17 and 5,411.46

Step by Step Solution

1. Step 1: Write the proportion equation
   11,986.81 : 17,978.17 = 5,411.46 : x
2. Step 2: Convert to fraction form
   11,986.81/17,978.17 = 5,411.46/x
3. Step 3: Cross multiply
   11,986.81x = 17,978.17 × 5,411.46
4. Step 4: Simplify right side
   11,986.81x = 97,288,087.91
5. Step 5: Solve for x
   x = 97,288,087.91/11,986.81
6. Step 6: Final answer
   x = 8,116.26