Finding the Fourth Proportional to 1,435.05, 1,980.25 and 805.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,435.05 : 1,980.25 = 805.55 : x
2. Step 2: Convert to fraction form
   1,435.05/1,980.25 = 805.55/x
3. Step 3: Cross multiply
   1,435.05x = 1,980.25 × 805.55
4. Step 4: Simplify right side
   1,435.05x = 1,595,178.47
5. Step 5: Solve for x
   x = 1,595,178.47/1,435.05
6. Step 6: Final answer
   x = 1,111.58