Finding the Fourth Proportional to 2,429.67, 3,639.27 and 1,389.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,429.67 : 3,639.27 = 1,389.12 : x
2. Step 2: Convert to fraction form
   2,429.67/3,639.27 = 1,389.12/x
3. Step 3: Cross multiply
   2,429.67x = 3,639.27 × 1,389.12
4. Step 4: Simplify right side
   2,429.67x = 5,055,382.74
5. Step 5: Solve for x
   x = 5,055,382.74/2,429.67
6. Step 6: Final answer
   x = 2,080.69