Finding the Fourth Proportional to 1,392.57, 1,921.17 and 867.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.57 : 1,921.17 = 867.69 : x
2. Step 2: Convert to fraction form
   1,392.57/1,921.17 = 867.69/x
3. Step 3: Cross multiply
   1,392.57x = 1,921.17 × 867.69
4. Step 4: Simplify right side
   1,392.57x = 1,666,980.00
5. Step 5: Solve for x
   x = 1,666,980.00/1,392.57
6. Step 6: Final answer
   x = 1,197.05