Finding the Fourth Proportional to 1,386.56, 1,922.57 and 1,340.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.56 : 1,922.57 = 1,340.30 : x
2. Step 2: Convert to fraction form
   1,386.56/1,922.57 = 1,340.30/x
3. Step 3: Cross multiply
   1,386.56x = 1,922.57 × 1,340.30
4. Step 4: Simplify right side
   1,386.56x = 2,576,820.57
5. Step 5: Solve for x
   x = 2,576,820.57/1,386.56
6. Step 6: Final answer
   x = 1,858.43