Finding the Fourth Proportional to 1,433.76, 1,978.24 and 812.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,433.76 : 1,978.24 = 812.64 : x
2. Step 2: Convert to fraction form
   1,433.76/1,978.24 = 812.64/x
3. Step 3: Cross multiply
   1,433.76x = 1,978.24 × 812.64
4. Step 4: Simplify right side
   1,433.76x = 1,607,596.95
5. Step 5: Solve for x
   x = 1,607,596.95/1,433.76
6. Step 6: Final answer
   x = 1,121.25