Finding the Fourth Proportional to 1,398.30, 1,928.36 and 1,118.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.30 : 1,928.36 = 1,118.54 : x
2. Step 2: Convert to fraction form
   1,398.30/1,928.36 = 1,118.54/x
3. Step 3: Cross multiply
   1,398.30x = 1,928.36 × 1,118.54
4. Step 4: Simplify right side
   1,398.30x = 2,156,955.41
5. Step 5: Solve for x
   x = 2,156,955.41/1,398.30
6. Step 6: Final answer
   x = 1,542.56