Finding the Fourth Proportional to 1,542.58, 2,128.81 and 879.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,542.58 : 2,128.81 = 879.42 : x
2. Step 2: Convert to fraction form
   1,542.58/2,128.81 = 879.42/x
3. Step 3: Cross multiply
   1,542.58x = 2,128.81 × 879.42
4. Step 4: Simplify right side
   1,542.58x = 1,872,118.09
5. Step 5: Solve for x
   x = 1,872,118.09/1,542.58
6. Step 6: Final answer
   x = 1,213.63