Finding the Fourth Proportional to 1,433.46, 1,978.47 and 909.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,433.46 : 1,978.47 = 909.78 : x
2. Step 2: Convert to fraction form
   1,433.46/1,978.47 = 909.78/x
3. Step 3: Cross multiply
   1,433.46x = 1,978.47 × 909.78
4. Step 4: Simplify right side
   1,433.46x = 1,799,972.44
5. Step 5: Solve for x
   x = 1,799,972.44/1,433.46
6. Step 6: Final answer
   x = 1,255.68