Finding the Fourth Proportional to 1,398.72, 2,096.82 and 1,321.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.72 : 2,096.82 = 1,321.38 : x
2. Step 2: Convert to fraction form
   1,398.72/2,096.82 = 1,321.38/x
3. Step 3: Cross multiply
   1,398.72x = 2,096.82 × 1,321.38
4. Step 4: Simplify right side
   1,398.72x = 2,770,696.01
5. Step 5: Solve for x
   x = 2,770,696.01/1,398.72
6. Step 6: Final answer
   x = 1,980.88