Finding the Fourth Proportional to 1,321.57, 1,982.56 and 1,321.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.57 : 1,982.56 = 1,321.57 : x
2. Step 2: Convert to fraction form
   1,321.57/1,982.56 = 1,321.57/x
3. Step 3: Cross multiply
   1,321.57x = 1,982.56 × 1,321.57
4. Step 4: Simplify right side
   1,321.57x = 2,620,091.82
5. Step 5: Solve for x
   x = 2,620,091.82/1,321.57
6. Step 6: Final answer
   x = 1,982.56