Finding the Fourth Proportional to 2,585.79, 3,879.05 and 830.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,585.79 : 3,879.05 = 830.38 : x
2. Step 2: Convert to fraction form
   2,585.79/3,879.05 = 830.38/x
3. Step 3: Cross multiply
   2,585.79x = 3,879.05 × 830.38
4. Step 4: Simplify right side
   2,585.79x = 3,221,085.54
5. Step 5: Solve for x
   x = 3,221,085.54/2,585.79
6. Step 6: Final answer
   x = 1,245.69