Finding the Fourth Proportional to 1,015.50, 1,398.27 and 865.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.50 : 1,398.27 = 865.79 : x
2. Step 2: Convert to fraction form
   1,015.50/1,398.27 = 865.79/x
3. Step 3: Cross multiply
   1,015.50x = 1,398.27 × 865.79
4. Step 4: Simplify right side
   1,015.50x = 1,210,604.81
5. Step 5: Solve for x
   x = 1,210,604.81/1,015.50
6. Step 6: Final answer
   x = 1,192.12