Finding the Fourth Proportional to 1,321.07, 1,978.69 and 1,143.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.07 : 1,978.69 = 1,143.27 : x
2. Step 2: Convert to fraction form
   1,321.07/1,978.69 = 1,143.27/x
3. Step 3: Cross multiply
   1,321.07x = 1,978.69 × 1,143.27
4. Step 4: Simplify right side
   1,321.07x = 2,262,176.92
5. Step 5: Solve for x
   x = 2,262,176.92/1,321.07
6. Step 6: Final answer
   x = 1,712.38