Finding the Fourth Proportional to 2,155.12, 3,230.38 and 1,228.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.12 : 3,230.38 = 1,228.69 : x
2. Step 2: Convert to fraction form
   2,155.12/3,230.38 = 1,228.69/x
3. Step 3: Cross multiply
   2,155.12x = 3,230.38 × 1,228.69
4. Step 4: Simplify right side
   2,155.12x = 3,969,126.46
5. Step 5: Solve for x
   x = 3,969,126.46/2,155.12
6. Step 6: Final answer
   x = 1,841.72