Finding the Fourth Proportional to 2,078.55, 3,116.78 and 691.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.55 : 3,116.78 = 691.39 : x
2. Step 2: Convert to fraction form
   2,078.55/3,116.78 = 691.39/x
3. Step 3: Cross multiply
   2,078.55x = 3,116.78 × 691.39
4. Step 4: Simplify right side
   2,078.55x = 2,154,914.86
5. Step 5: Solve for x
   x = 2,154,914.86/2,078.55
6. Step 6: Final answer
   x = 1,036.74