Finding the Fourth Proportional to 1,442.59, 1,990.75 and 813.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.59 : 1,990.75 = 813.12 : x
2. Step 2: Convert to fraction form
   1,442.59/1,990.75 = 813.12/x
3. Step 3: Cross multiply
   1,442.59x = 1,990.75 × 813.12
4. Step 4: Simplify right side
   1,442.59x = 1,618,716.61
5. Step 5: Solve for x
   x = 1,618,716.61/1,442.59
6. Step 6: Final answer
   x = 1,122.09