Finding the Fourth Proportional to 2,142.15, 3,213.56 and 909.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.15 : 3,213.56 = 909.56 : x
2. Step 2: Convert to fraction form
   2,142.15/3,213.56 = 909.56/x
3. Step 3: Cross multiply
   2,142.15x = 3,213.56 × 909.56
4. Step 4: Simplify right side
   2,142.15x = 2,922,930.83
5. Step 5: Solve for x
   x = 2,922,930.83/2,142.15
6. Step 6: Final answer
   x = 1,364.49