Finding the Fourth Proportional to 2,078.09, 3,117.60 and 691.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.09 : 3,117.60 = 691.31 : x
2. Step 2: Convert to fraction form
   2,078.09/3,117.60 = 691.31/x
3. Step 3: Cross multiply
   2,078.09x = 3,117.60 × 691.31
4. Step 4: Simplify right side
   2,078.09x = 2,155,228.06
5. Step 5: Solve for x
   x = 2,155,228.06/2,078.09
6. Step 6: Final answer
   x = 1,037.12