Finding the Fourth Proportional to 1,578.52, 2,178.37 and 870.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,578.52 : 2,178.37 = 870.42 : x
2. Step 2: Convert to fraction form
   1,578.52/2,178.37 = 870.42/x
3. Step 3: Cross multiply
   1,578.52x = 2,178.37 × 870.42
4. Step 4: Simplify right side
   1,578.52x = 1,896,096.82
5. Step 5: Solve for x
   x = 1,896,096.82/1,578.52
6. Step 6: Final answer
   x = 1,201.19