Finding the Fourth Proportional to 2,189.72, 3,284.94 and 728.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,189.72 : 3,284.94 = 728.72 : x
2. Step 2: Convert to fraction form
   2,189.72/3,284.94 = 728.72/x
3. Step 3: Cross multiply
   2,189.72x = 3,284.94 × 728.72
4. Step 4: Simplify right side
   2,189.72x = 2,393,801.48
5. Step 5: Solve for x
   x = 2,393,801.48/2,189.72
6. Step 6: Final answer
   x = 1,093.20