Finding the Fourth Proportional to 1,386.35, 1,912.79 and 826.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.35 : 1,912.79 = 826.56 : x
2. Step 2: Convert to fraction form
   1,386.35/1,912.79 = 826.56/x
3. Step 3: Cross multiply
   1,386.35x = 1,912.79 × 826.56
4. Step 4: Simplify right side
   1,386.35x = 1,581,031.57
5. Step 5: Solve for x
   x = 1,581,031.57/1,386.35
6. Step 6: Final answer
   x = 1,140.43