Finding the Fourth Proportional to 1,391.93, 1,919.40 and 867.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.93 : 1,919.40 = 867.05 : x
2. Step 2: Convert to fraction form
   1,391.93/1,919.40 = 867.05/x
3. Step 3: Cross multiply
   1,391.93x = 1,919.40 × 867.05
4. Step 4: Simplify right side
   1,391.93x = 1,664,215.77
5. Step 5: Solve for x
   x = 1,664,215.77/1,391.93
6. Step 6: Final answer
   x = 1,195.62