Finding the Fourth Proportional to 1,442.69, 1,990.86 and 813.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.69 : 1,990.86 = 813.26 : x
2. Step 2: Convert to fraction form
   1,442.69/1,990.86 = 813.26/x
3. Step 3: Cross multiply
   1,442.69x = 1,990.86 × 813.26
4. Step 4: Simplify right side
   1,442.69x = 1,619,086.80
5. Step 5: Solve for x
   x = 1,619,086.80/1,442.69
6. Step 6: Final answer
   x = 1,122.27