Finding the Fourth Proportional to 1,435.64, 1,983.78 and 1,121.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,435.64 : 1,983.78 = 1,121.72 : x
2. Step 2: Convert to fraction form
   1,435.64/1,983.78 = 1,121.72/x
3. Step 3: Cross multiply
   1,435.64x = 1,983.78 × 1,121.72
4. Step 4: Simplify right side
   1,435.64x = 2,225,245.70
5. Step 5: Solve for x
   x = 2,225,245.70/1,435.64
6. Step 6: Final answer
   x = 1,550.00