Finding the Fourth Proportional to 1,441.90, 1,989.76 and 812.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,441.90 : 1,989.76 = 812.47 : x
2. Step 2: Convert to fraction form
   1,441.90/1,989.76 = 812.47/x
3. Step 3: Cross multiply
   1,441.90x = 1,989.76 × 812.47
4. Step 4: Simplify right side
   1,441.90x = 1,616,620.31
5. Step 5: Solve for x
   x = 1,616,620.31/1,441.90
6. Step 6: Final answer
   x = 1,121.17