Finding the Fourth Proportional to 2,380.82, 3,285.72 and 1,386.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,380.82 : 3,285.72 = 1,386.40 : x
2. Step 2: Convert to fraction form
   2,380.82/3,285.72 = 1,386.40/x
3. Step 3: Cross multiply
   2,380.82x = 3,285.72 × 1,386.40
4. Step 4: Simplify right side
   2,380.82x = 4,555,322.21
5. Step 5: Solve for x
   x = 4,555,322.21/2,380.82
6. Step 6: Final answer
   x = 1,913.34