Finding the Fourth Proportional to 2,439.02, 3,365.34 and 1,390.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,439.02 : 3,365.34 = 1,390.88 : x
2. Step 2: Convert to fraction form
   2,439.02/3,365.34 = 1,390.88/x
3. Step 3: Cross multiply
   2,439.02x = 3,365.34 × 1,390.88
4. Step 4: Simplify right side
   2,439.02x = 4,680,784.10
5. Step 5: Solve for x
   x = 4,680,784.10/2,439.02
6. Step 6: Final answer
   x = 1,919.12