Finding the Fourth Proportional to 1,433.69, 1,978.49 and 812.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,433.69 : 1,978.49 = 812.69 : x
2. Step 2: Convert to fraction form
   1,433.69/1,978.49 = 812.69/x
3. Step 3: Cross multiply
   1,433.69x = 1,978.49 × 812.69
4. Step 4: Simplify right side
   1,433.69x = 1,607,899.04
5. Step 5: Solve for x
   x = 1,607,899.04/1,433.69
6. Step 6: Final answer
   x = 1,121.51