Finding the Fourth Proportional to 867.39, 1,293.86 and 785.31

Step by Step Solution

1. Step 1: Write the proportion equation
   867.39 : 1,293.86 = 785.31 : x
2. Step 2: Convert to fraction form
   867.39/1,293.86 = 785.31/x
3. Step 3: Cross multiply
   867.39x = 1,293.86 × 785.31
4. Step 4: Simplify right side
   867.39x = 1,016,077.27
5. Step 5: Solve for x
   x = 1,016,077.27/867.39
6. Step 6: Final answer
   x = 1,171.42