Finding the Fourth Proportional to 2,155.56, 2,974.77 and 1,689

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.56 : 2,974.77 = 1,689 : x
2. Step 2: Convert to fraction form
   2,155.56/2,974.77 = 1,689/x
3. Step 3: Cross multiply
   2,155.56x = 2,974.77 × 1,689
4. Step 4: Simplify right side
   2,155.56x = 5,024,386.53
5. Step 5: Solve for x
   x = 5,024,386.53/2,155.56
6. Step 6: Final answer
   x = 2,330.90