Finding the Fourth Proportional to 1,389.82, 1,918.41 and 800.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.82 : 1,918.41 = 800.50 : x
2. Step 2: Convert to fraction form
   1,389.82/1,918.41 = 800.50/x
3. Step 3: Cross multiply
   1,389.82x = 1,918.41 × 800.50
4. Step 4: Simplify right side
   1,389.82x = 1,535,687.21
5. Step 5: Solve for x
   x = 1,535,687.21/1,389.82
6. Step 6: Final answer
   x = 1,104.95