Finding the Fourth Proportional to 2,485.98, 3,729.45 and 842.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,485.98 : 3,729.45 = 842.64 : x
2. Step 2: Convert to fraction form
   2,485.98/3,729.45 = 842.64/x
3. Step 3: Cross multiply
   2,485.98x = 3,729.45 × 842.64
4. Step 4: Simplify right side
   2,485.98x = 3,142,583.75
5. Step 5: Solve for x
   x = 3,142,583.75/2,485.98
6. Step 6: Final answer
   x = 1,264.12