Finding the Fourth Proportional to 1,390.04, 1,918.20 and 800.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.04 : 1,918.20 = 800.46 : x
2. Step 2: Convert to fraction form
   1,390.04/1,918.20 = 800.46/x
3. Step 3: Cross multiply
   1,390.04x = 1,918.20 × 800.46
4. Step 4: Simplify right side
   1,390.04x = 1,535,442.37
5. Step 5: Solve for x
   x = 1,535,442.37/1,390.04
6. Step 6: Final answer
   x = 1,104.60