Finding the Fourth Proportional to 1,386.05, 1,912.99 and 826.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.05 : 1,912.99 = 826.55 : x
2. Step 2: Convert to fraction form
   1,386.05/1,912.99 = 826.55/x
3. Step 3: Cross multiply
   1,386.05x = 1,912.99 × 826.55
4. Step 4: Simplify right side
   1,386.05x = 1,581,184.60
5. Step 5: Solve for x
   x = 1,581,184.60/1,386.05
6. Step 6: Final answer
   x = 1,140.79