Finding the Fourth Proportional to 2,679.47, 4,018.69 and 830.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,679.47 : 4,018.69 = 830.31 : x
2. Step 2: Convert to fraction form
   2,679.47/4,018.69 = 830.31/x
3. Step 3: Cross multiply
   2,679.47x = 4,018.69 × 830.31
4. Step 4: Simplify right side
   2,679.47x = 3,336,758.49
5. Step 5: Solve for x
   x = 3,336,758.49/2,679.47
6. Step 6: Final answer
   x = 1,245.31