Finding the Fourth Proportional to 1,428.54, 2,139.52 and 1,379.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.54 : 2,139.52 = 1,379.30 : x
2. Step 2: Convert to fraction form
   1,428.54/2,139.52 = 1,379.30/x
3. Step 3: Cross multiply
   1,428.54x = 2,139.52 × 1,379.30
4. Step 4: Simplify right side
   1,428.54x = 2,951,039.94
5. Step 5: Solve for x
   x = 2,951,039.94/1,428.54
6. Step 6: Final answer
   x = 2,065.77