Finding the Fourth Proportional to 3,978.40, 5,489.76 and 3,196.48

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.40 : 5,489.76 = 3,196.48 : x
2. Step 2: Convert to fraction form
   3,978.40/5,489.76 = 3,196.48/x
3. Step 3: Cross multiply
   3,978.40x = 5,489.76 × 3,196.48
4. Step 4: Simplify right side
   3,978.40x = 17,547,908.04
5. Step 5: Solve for x
   x = 17,547,908.04/3,978.40
6. Step 6: Final answer
   x = 4,410.80