Finding the Fourth Proportional to 3,978.38, 5,490.18 and 2,186.01

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.38 : 5,490.18 = 2,186.01 : x
2. Step 2: Convert to fraction form
   3,978.38/5,490.18 = 2,186.01/x
3. Step 3: Cross multiply
   3,978.38x = 5,490.18 × 2,186.01
4. Step 4: Simplify right side
   3,978.38x = 12,001,569.08
5. Step 5: Solve for x
   x = 12,001,569.08/3,978.38
6. Step 6: Final answer
   x = 3,016.69