Finding the Fourth Proportional to 1,298.89, 1,791.88 and 801.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.89 : 1,791.88 = 801.55 : x
2. Step 2: Convert to fraction form
   1,298.89/1,791.88 = 801.55/x
3. Step 3: Cross multiply
   1,298.89x = 1,791.88 × 801.55
4. Step 4: Simplify right side
   1,298.89x = 1,436,281.41
5. Step 5: Solve for x
   x = 1,436,281.41/1,298.89
6. Step 6: Final answer
   x = 1,105.78