Finding the Fourth Proportional to 1,438.40, 1,983.56 and 1,085.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.40 : 1,983.56 = 1,085.18 : x
2. Step 2: Convert to fraction form
   1,438.40/1,983.56 = 1,085.18/x
3. Step 3: Cross multiply
   1,438.40x = 1,983.56 × 1,085.18
4. Step 4: Simplify right side
   1,438.40x = 2,152,519.64
5. Step 5: Solve for x
   x = 2,152,519.64/1,438.40
6. Step 6: Final answer
   x = 1,496.47