Finding the Fourth Proportional to 11,988.40, 17,978.04 and 3,665.84

Step by Step Solution

1. Step 1: Write the proportion equation
   11,988.40 : 17,978.04 = 3,665.84 : x
2. Step 2: Convert to fraction form
   11,988.40/17,978.04 = 3,665.84/x
3. Step 3: Cross multiply
   11,988.40x = 17,978.04 × 3,665.84
4. Step 4: Simplify right side
   11,988.40x = 65,904,618.15
5. Step 5: Solve for x
   x = 65,904,618.15/11,988.40
6. Step 6: Final answer
   x = 5,497.37