Finding the Fourth Proportional to 1,421.31, 1,961.41 and 800.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.31 : 1,961.41 = 800.31 : x
2. Step 2: Convert to fraction form
   1,421.31/1,961.41 = 800.31/x
3. Step 3: Cross multiply
   1,421.31x = 1,961.41 × 800.31
4. Step 4: Simplify right side
   1,421.31x = 1,569,736.04
5. Step 5: Solve for x
   x = 1,569,736.04/1,421.31
6. Step 6: Final answer
   x = 1,104.43