Finding the Fourth Proportional to 2,618.32, 3,613.12 and 1,439.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,618.32 : 3,613.12 = 1,439.20 : x
2. Step 2: Convert to fraction form
   2,618.32/3,613.12 = 1,439.20/x
3. Step 3: Cross multiply
   2,618.32x = 3,613.12 × 1,439.20
4. Step 4: Simplify right side
   2,618.32x = 5,200,002.30
5. Step 5: Solve for x
   x = 5,200,002.30/2,618.32
6. Step 6: Final answer
   x = 1,986.01