Finding the Fourth Proportional to 5,621.46, 8,436.78 and 3,979.60

Step by Step Solution

1. Step 1: Write the proportion equation
   5,621.46 : 8,436.78 = 3,979.60 : x
2. Step 2: Convert to fraction form
   5,621.46/8,436.78 = 3,979.60/x
3. Step 3: Cross multiply
   5,621.46x = 8,436.78 × 3,979.60
4. Step 4: Simplify right side
   5,621.46x = 33,575,009.69
5. Step 5: Solve for x
   x = 33,575,009.69/5,621.46
6. Step 6: Final answer
   x = 5,972.65