Finding the Fourth Proportional to 2,171.98, 3,257.30 and 785.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.98 : 3,257.30 = 785.15 : x
2. Step 2: Convert to fraction form
   2,171.98/3,257.30 = 785.15/x
3. Step 3: Cross multiply
   2,171.98x = 3,257.30 × 785.15
4. Step 4: Simplify right side
   2,171.98x = 2,557,469.10
5. Step 5: Solve for x
   x = 2,557,469.10/2,171.98
6. Step 6: Final answer
   x = 1,177.48