Finding the Fourth Proportional to 2,579.78, 3,869.69 and 1,019.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,579.78 : 3,869.69 = 1,019.72 : x
2. Step 2: Convert to fraction form
   2,579.78/3,869.69 = 1,019.72/x
3. Step 3: Cross multiply
   2,579.78x = 3,869.69 × 1,019.72
4. Step 4: Simplify right side
   2,579.78x = 3,946,004.86
5. Step 5: Solve for x
   x = 3,946,004.86/2,579.78
6. Step 6: Final answer
   x = 1,529.59