Finding the Fourth Proportional to 1,978.92, 2,731.05 and 1,128.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.92 : 2,731.05 = 1,128.15 : x
2. Step 2: Convert to fraction form
   1,978.92/2,731.05 = 1,128.15/x
3. Step 3: Cross multiply
   1,978.92x = 2,731.05 × 1,128.15
4. Step 4: Simplify right side
   1,978.92x = 3,081,034.06
5. Step 5: Solve for x
   x = 3,081,034.06/1,978.92
6. Step 6: Final answer
   x = 1,556.93