Finding the Fourth Proportional to 1,638.47, 2,443.87 and 1,392.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.47 : 2,443.87 = 1,392.23 : x
2. Step 2: Convert to fraction form
   1,638.47/2,443.87 = 1,392.23/x
3. Step 3: Cross multiply
   1,638.47x = 2,443.87 × 1,392.23
4. Step 4: Simplify right side
   1,638.47x = 3,402,429.13
5. Step 5: Solve for x
   x = 3,402,429.13/1,638.47
6. Step 6: Final answer
   x = 2,076.59