Finding the Fourth Proportional to 1,285.31, 1,918.59 and 1,103.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,285.31 : 1,918.59 = 1,103.87 : x
2. Step 2: Convert to fraction form
   1,285.31/1,918.59 = 1,103.87/x
3. Step 3: Cross multiply
   1,285.31x = 1,918.59 × 1,103.87
4. Step 4: Simplify right side
   1,285.31x = 2,117,873.94
5. Step 5: Solve for x
   x = 2,117,873.94/1,285.31
6. Step 6: Final answer
   x = 1,647.75