Finding the Fourth Proportional to 2,159.89, 2,980.67 and 1,228.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,159.89 : 2,980.67 = 1,228.39 : x
2. Step 2: Convert to fraction form
   2,159.89/2,980.67 = 1,228.39/x
3. Step 3: Cross multiply
   2,159.89x = 2,980.67 × 1,228.39
4. Step 4: Simplify right side
   2,159.89x = 3,661,425.22
5. Step 5: Solve for x
   x = 3,661,425.22/2,159.89
6. Step 6: Final answer
   x = 1,695.19