Finding the Fourth Proportional to 2,155.20, 2,974.16 and 1,223.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.20 : 2,974.16 = 1,223.52 : x
2. Step 2: Convert to fraction form
   2,155.20/2,974.16 = 1,223.52/x
3. Step 3: Cross multiply
   2,155.20x = 2,974.16 × 1,223.52
4. Step 4: Simplify right side
   2,155.20x = 3,638,944.24
5. Step 5: Solve for x
   x = 3,638,944.24/2,155.20
6. Step 6: Final answer
   x = 1,688.45