Finding the Fourth Proportional to 1,542.38, 2,128.61 and 879.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,542.38 : 2,128.61 = 879.12 : x
2. Step 2: Convert to fraction form
   1,542.38/2,128.61 = 879.12/x
3. Step 3: Cross multiply
   1,542.38x = 2,128.61 × 879.12
4. Step 4: Simplify right side
   1,542.38x = 1,871,305.82
5. Step 5: Solve for x
   x = 1,871,305.82/1,542.38
6. Step 6: Final answer
   x = 1,213.26