Finding the Fourth Proportional to 2,053.57, 2,831.68 and 1,389.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,053.57 : 2,831.68 = 1,389.28 : x
2. Step 2: Convert to fraction form
   2,053.57/2,831.68 = 1,389.28/x
3. Step 3: Cross multiply
   2,053.57x = 2,831.68 × 1,389.28
4. Step 4: Simplify right side
   2,053.57x = 3,933,996.39
5. Step 5: Solve for x
   x = 3,933,996.39/2,053.57
6. Step 6: Final answer
   x = 1,915.69