Finding the Fourth Proportional to 2,553.43, 3,828.20 and 1,320.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,553.43 : 3,828.20 = 1,320.05 : x
2. Step 2: Convert to fraction form
   2,553.43/3,828.20 = 1,320.05/x
3. Step 3: Cross multiply
   2,553.43x = 3,828.20 × 1,320.05
4. Step 4: Simplify right side
   2,553.43x = 5,053,422.09
5. Step 5: Solve for x
   x = 5,053,422.09/2,553.43
6. Step 6: Final answer
   x = 1,979.07