Finding the Fourth Proportional to 1,435.15, 1,980.33 and 805.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,435.15 : 1,980.33 = 805.72 : x
2. Step 2: Convert to fraction form
   1,435.15/1,980.33 = 805.72/x
3. Step 3: Cross multiply
   1,435.15x = 1,980.33 × 805.72
4. Step 4: Simplify right side
   1,435.15x = 1,595,591.49
5. Step 5: Solve for x
   x = 1,595,591.49/1,435.15
6. Step 6: Final answer
   x = 1,111.79