Finding the Fourth Proportional to 11,985.44, 17,978.05 and 3,665.42

Step by Step Solution

1. Step 1: Write the proportion equation
   11,985.44 : 17,978.05 = 3,665.42 : x
2. Step 2: Convert to fraction form
   11,985.44/17,978.05 = 3,665.42/x
3. Step 3: Cross multiply
   11,985.44x = 17,978.05 × 3,665.42
4. Step 4: Simplify right side
   11,985.44x = 65,897,086.14
5. Step 5: Solve for x
   x = 65,897,086.14/11,985.44
6. Step 6: Final answer
   x = 5,498.10