Finding the Fourth Proportional to 1,578.86, 2,179.72 and 1,020.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,578.86 : 2,179.72 = 1,020.15 : x
2. Step 2: Convert to fraction form
   1,578.86/2,179.72 = 1,020.15/x
3. Step 3: Cross multiply
   1,578.86x = 2,179.72 × 1,020.15
4. Step 4: Simplify right side
   1,578.86x = 2,223,641.36
5. Step 5: Solve for x
   x = 2,223,641.36/1,578.86
6. Step 6: Final answer
   x = 1,408.38