Finding the Fourth Proportional to 1,443.76, 1,990.06 and 1,128.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.76 : 1,990.06 = 1,128.48 : x
2. Step 2: Convert to fraction form
   1,443.76/1,990.06 = 1,128.48/x
3. Step 3: Cross multiply
   1,443.76x = 1,990.06 × 1,128.48
4. Step 4: Simplify right side
   1,443.76x = 2,245,742.91
5. Step 5: Solve for x
   x = 2,245,742.91/1,443.76
6. Step 6: Final answer
   x = 1,555.48