Finding the Fourth Proportional to 2,386.81, 3,293.55 and 1,391.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,386.81 : 3,293.55 = 1,391.89 : x
2. Step 2: Convert to fraction form
   2,386.81/3,293.55 = 1,391.89/x
3. Step 3: Cross multiply
   2,386.81x = 3,293.55 × 1,391.89
4. Step 4: Simplify right side
   2,386.81x = 4,584,259.31
5. Step 5: Solve for x
   x = 4,584,259.31/2,386.81
6. Step 6: Final answer
   x = 1,920.66