Finding the Fourth Proportional to 1,386.54, 1,912.50 and 862.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.54 : 1,912.50 = 862.83 : x
2. Step 2: Convert to fraction form
   1,386.54/1,912.50 = 862.83/x
3. Step 3: Cross multiply
   1,386.54x = 1,912.50 × 862.83
4. Step 4: Simplify right side
   1,386.54x = 1,650,162.38
5. Step 5: Solve for x
   x = 1,650,162.38/1,386.54
6. Step 6: Final answer
   x = 1,190.13