Finding the Fourth Proportional to 3,787.31, 5,679.33 and 1,321.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,787.31 : 5,679.33 = 1,321.40 : x
2. Step 2: Convert to fraction form
   3,787.31/5,679.33 = 1,321.40/x
3. Step 3: Cross multiply
   3,787.31x = 5,679.33 × 1,321.40
4. Step 4: Simplify right side
   3,787.31x = 7,504,638.27
5. Step 5: Solve for x
   x = 7,504,638.27/3,787.31
6. Step 6: Final answer
   x = 1,981.52