Finding the Fourth Proportional to 3,945.40, 5,442.36 and 2,528.59

Step by Step Solution

1. Step 1: Write the proportion equation
   3,945.40 : 5,442.36 = 2,528.59 : x
2. Step 2: Convert to fraction form
   3,945.40/5,442.36 = 2,528.59/x
3. Step 3: Cross multiply
   3,945.40x = 5,442.36 × 2,528.59
4. Step 4: Simplify right side
   3,945.40x = 13,761,479.55
5. Step 5: Solve for x
   x = 13,761,479.55/3,945.40
6. Step 6: Final answer
   x = 3,487.98