Finding the Fourth Proportional to 2,078.30, 3,116.55 and 845.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.30 : 3,116.55 = 845.30 : x
2. Step 2: Convert to fraction form
   2,078.30/3,116.55 = 845.30/x
3. Step 3: Cross multiply
   2,078.30x = 3,116.55 × 845.30
4. Step 4: Simplify right side
   2,078.30x = 2,634,419.72
5. Step 5: Solve for x
   x = 2,634,419.72/2,078.30
6. Step 6: Final answer
   x = 1,267.58