Finding the Fourth Proportional to 2,160.39, 2,981.37 and 1,228.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,160.39 : 2,981.37 = 1,228.89 : x
2. Step 2: Convert to fraction form
   2,160.39/2,981.37 = 1,228.89/x
3. Step 3: Cross multiply
   2,160.39x = 2,981.37 × 1,228.89
4. Step 4: Simplify right side
   2,160.39x = 3,663,775.78
5. Step 5: Solve for x
   x = 3,663,775.78/2,160.39
6. Step 6: Final answer
   x = 1,695.89