Finding the Fourth Proportional to 1,386.08, 1,912.74 and 826.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.08 : 1,912.74 = 826.41 : x
2. Step 2: Convert to fraction form
   1,386.08/1,912.74 = 826.41/x
3. Step 3: Cross multiply
   1,386.08x = 1,912.74 × 826.41
4. Step 4: Simplify right side
   1,386.08x = 1,580,711.54
5. Step 5: Solve for x
   x = 1,580,711.54/1,386.08
6. Step 6: Final answer
   x = 1,140.42