Finding the Fourth Proportional to 2,128.08, 2,936.28 and 1,231.59

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.08 : 2,936.28 = 1,231.59 : x
2. Step 2: Convert to fraction form
   2,128.08/2,936.28 = 1,231.59/x
3. Step 3: Cross multiply
   2,128.08x = 2,936.28 × 1,231.59
4. Step 4: Simplify right side
   2,128.08x = 3,616,293.09
5. Step 5: Solve for x
   x = 3,616,293.09/2,128.08
6. Step 6: Final answer
   x = 1,699.32