Finding the Fourth Proportional to 1,390.23, 1,918.35 and 800.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.23 : 1,918.35 = 800.73 : x
2. Step 2: Convert to fraction form
   1,390.23/1,918.35 = 800.73/x
3. Step 3: Cross multiply
   1,390.23x = 1,918.35 × 800.73
4. Step 4: Simplify right side
   1,390.23x = 1,536,080.40
5. Step 5: Solve for x
   x = 1,536,080.40/1,390.23
6. Step 6: Final answer
   x = 1,104.91