Finding the Fourth Proportional to 2,485.32, 3,729.56 and 1,390.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,485.32 : 3,729.56 = 1,390.40 : x
2. Step 2: Convert to fraction form
   2,485.32/3,729.56 = 1,390.40/x
3. Step 3: Cross multiply
   2,485.32x = 3,729.56 × 1,390.40
4. Step 4: Simplify right side
   2,485.32x = 5,185,580.22
5. Step 5: Solve for x
   x = 5,185,580.22/2,485.32
6. Step 6: Final answer
   x = 2,086.48