Finding the Fourth Proportional to 2,618.40, 3,613.57 and 1,439.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,618.40 : 3,613.57 = 1,439.47 : x
2. Step 2: Convert to fraction form
   2,618.40/3,613.57 = 1,439.47/x
3. Step 3: Cross multiply
   2,618.40x = 3,613.57 × 1,439.47
4. Step 4: Simplify right side
   2,618.40x = 5,201,600.34
5. Step 5: Solve for x
   x = 5,201,600.34/2,618.40
6. Step 6: Final answer
   x = 1,986.56