Finding the Fourth Proportional to 3,979.42, 5,527.60 and 3,915.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,979.42 : 5,527.60 = 3,915.86 : x
2. Step 2: Convert to fraction form
   3,979.42/5,527.60 = 3,915.86/x
3. Step 3: Cross multiply
   3,979.42x = 5,527.60 × 3,915.86
4. Step 4: Simplify right side
   3,979.42x = 21,645,270.31
5. Step 5: Solve for x
   x = 21,645,270.31/3,979.42
6. Step 6: Final answer
   x = 5,439.31