Finding the Fourth Proportional to 1,428.33, 2,143.23 and 1,081.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.33 : 2,143.23 = 1,081.55 : x
2. Step 2: Convert to fraction form
   1,428.33/2,143.23 = 1,081.55/x
3. Step 3: Cross multiply
   1,428.33x = 2,143.23 × 1,081.55
4. Step 4: Simplify right side
   1,428.33x = 2,317,999.69
5. Step 5: Solve for x
   x = 2,317,999.69/1,428.33
6. Step 6: Final answer
   x = 1,622.87