Finding the Fourth Proportional to 1,542.57, 2,128.71 and 879.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,542.57 : 2,128.71 = 879.39 : x
2. Step 2: Convert to fraction form
   1,542.57/2,128.71 = 879.39/x
3. Step 3: Cross multiply
   1,542.57x = 2,128.71 × 879.39
4. Step 4: Simplify right side
   1,542.57x = 1,871,966.29
5. Step 5: Solve for x
   x = 1,871,966.29/1,542.57
6. Step 6: Final answer
   x = 1,213.54