Finding the Fourth Proportional to 2,139.70, 2,945.91 and 1,863.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.70 : 2,945.91 = 1,863.58 : x
2. Step 2: Convert to fraction form
   2,139.70/2,945.91 = 1,863.58/x
3. Step 3: Cross multiply
   2,139.70x = 2,945.91 × 1,863.58
4. Step 4: Simplify right side
   2,139.70x = 5,489,938.96
5. Step 5: Solve for x
   x = 5,489,938.96/2,139.70
6. Step 6: Final answer
   x = 2,565.75