Finding the Fourth Proportional to 2,608.42, 3,912.68 and 853.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,608.42 : 3,912.68 = 853.42 : x
2. Step 2: Convert to fraction form
   2,608.42/3,912.68 = 853.42/x
3. Step 3: Cross multiply
   2,608.42x = 3,912.68 × 853.42
4. Step 4: Simplify right side
   2,608.42x = 3,339,159.37
5. Step 5: Solve for x
   x = 3,339,159.37/2,608.42
6. Step 6: Final answer
   x = 1,280.15