Finding the Fourth Proportional to 2,885.55, 4,328.42 and 911.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,885.55 : 4,328.42 = 911.20 : x
2. Step 2: Convert to fraction form
   2,885.55/4,328.42 = 911.20/x
3. Step 3: Cross multiply
   2,885.55x = 4,328.42 × 911.20
4. Step 4: Simplify right side
   2,885.55x = 3,944,056.30
5. Step 5: Solve for x
   x = 3,944,056.30/2,885.55
6. Step 6: Final answer
   x = 1,366.83