Finding the Fourth Proportional to 2,615.78, 3,923.69 and 885.62

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.78 : 3,923.69 = 885.62 : x
2. Step 2: Convert to fraction form
   2,615.78/3,923.69 = 885.62/x
3. Step 3: Cross multiply
   2,615.78x = 3,923.69 × 885.62
4. Step 4: Simplify right side
   2,615.78x = 3,474,903.72
5. Step 5: Solve for x
   x = 3,474,903.72/2,615.78
6. Step 6: Final answer
   x = 1,328.44