Finding the Fourth Proportional to 2,155.47, 2,974.61 and 1,211.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.47 : 2,974.61 = 1,211.35 : x
2. Step 2: Convert to fraction form
   2,155.47/2,974.61 = 1,211.35/x
3. Step 3: Cross multiply
   2,155.47x = 2,974.61 × 1,211.35
4. Step 4: Simplify right side
   2,155.47x = 3,603,296.86
5. Step 5: Solve for x
   x = 3,603,296.86/2,155.47
6. Step 6: Final answer
   x = 1,671.70