Finding the Fourth Proportional to 1,391.78, 1,919.48 and 1,096.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.78 : 1,919.48 = 1,096.58 : x
2. Step 2: Convert to fraction form
   1,391.78/1,919.48 = 1,096.58/x
3. Step 3: Cross multiply
   1,391.78x = 1,919.48 × 1,096.58
4. Step 4: Simplify right side
   1,391.78x = 2,104,863.38
5. Step 5: Solve for x
   x = 2,104,863.38/1,391.78
6. Step 6: Final answer
   x = 1,512.35