Finding the Fourth Proportional to 2,113.85, 3,171.71 and 728.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,113.85 : 3,171.71 = 728.18 : x
2. Step 2: Convert to fraction form
   2,113.85/3,171.71 = 728.18/x
3. Step 3: Cross multiply
   2,113.85x = 3,171.71 × 728.18
4. Step 4: Simplify right side
   2,113.85x = 2,309,575.79
5. Step 5: Solve for x
   x = 2,309,575.79/2,113.85
6. Step 6: Final answer
   x = 1,092.59